Q.1 What does the acronym BET stand for in surface area analysis of biomaterials?
Brunauer, Emmett, Teller
Baker, Ellis, Thomas
Boron, Ethylene, Titanium
Binary, Electrostatic, Thermodynamics
Explanation - BET stands for Brunauer, Emmett, Teller, the scientists who developed the theory for measuring surface area using gas adsorption.
Correct answer is: Brunauer, Emmett, Teller
Q.2 Which technique is commonly used to measure the mechanical stiffness of a scaffold?
Nanoindentation
Mass spectrometry
Ultrasound imaging
Fluorescence microscopy
Explanation - Nanoindentation applies a known force with a sharp tip and measures deformation to calculate stiffness (Young's modulus) of small biomaterial samples.
Correct answer is: Nanoindentation
Q.3 A material shows a sudden drop in weight after immersion in PBS. What does this indicate?
Thermal degradation
Hydrolytic degradation
Oxidative degradation
Photodegradation
Explanation - Weight loss after water immersion is typical of hydrolytic degradation, where water molecules cleave polymer bonds.
Correct answer is: Hydrolytic degradation
Q.4 Which microscopy method provides three-dimensional surface topology of a biomaterial?
Confocal Laser Scanning Microscopy
Atomic Force Microscopy
Transmission Electron Microscopy
Scanning Electron Microscopy
Explanation - AFM uses a nanoscale tip to scan the surface, giving high‑resolution 3D topographic images of biomaterial surfaces.
Correct answer is: Atomic Force Microscopy
Q.5 During FTIR spectroscopy, which band is indicative of amide I vibrations?
1700–1600 cm⁻¹
3000–2800 cm⁻¹
1400–1300 cm⁻¹
600–400 cm⁻¹
Explanation - Amide I arises mainly from C=O stretching and appears near 1700–1600 cm⁻¹ in FTIR spectra.
Correct answer is: 1700–1600 cm⁻¹
Q.6 The surface wettability of a biomaterial is typically measured by which of the following?
Contact angle
Viscosity
Electrical conductivity
Molecular weight
Explanation - Contact angle measures how a liquid droplet spreads on a surface; lower angles mean higher wettability.
Correct answer is: Contact angle
Q.7 What does the TGA (Thermogravimetric Analysis) primarily assess?
Mass loss as temperature increases
Electrical resistance over time
Optical transmittance
Particle size distribution
Explanation - TGA records weight change of a material with rising temperature, indicating thermal stability and composition.
Correct answer is: Mass loss as temperature increases
Q.8 Which assay is commonly used to evaluate cytotoxicity of a biomaterial extract?
MTT assay
DLS analysis
XRD pattern
Raman shift
Explanation - MTT measures cell viability by reduction of tetrazolium salt; decreased absorbance indicates cytotoxicity.
Correct answer is: MTT assay
Q.9 X‑ray diffraction (XRD) is mainly used to determine what property of a biomaterial?
Crystallographic structure
Surface roughness
Chemical bonding
Electrical impedance
Explanation - XRD provides diffraction patterns that reveal the crystalline phases present in a material.
Correct answer is: Crystallographic structure
Q.10 Which property is NOT directly measured by a universal testing machine?
Tensile strength
Hardness
Elongation at break
Young's modulus
Explanation - Hardness requires indentation tests; a universal testing machine measures tensile or compressive force.
Correct answer is: Hardness
Q.11 In a water uptake test, a polymer’s % weight increase indicates its:
Swelling behavior
Electrical conductivity
Thermal expansion
Optical density
Explanation - Weight gain in water reflects the polymer’s ability to absorb fluid and swell.
Correct answer is: Swelling behavior
Q.12 What is the primary advantage of using micro‑computed tomography (µCT) for bone scaffolds?
Non‑destructive 3D imaging of pores
High‑resolution chemical composition
Real‑time mechanical testing
Surface roughness measurement
Explanation - µCT reconstructs internal pore architecture in 3D without damaging the sample.
Correct answer is: Non‑destructive 3D imaging of pores
Q.13 Which spectroscopic technique is best suited to determine the degree of crystallinity in a polymeric scaffold?
XRD
UV‑Vis
Raman
NMR
Explanation - XRD patterns show distinct peaks for crystalline phases, allowing calculation of crystallinity.
Correct answer is: XRD
Q.14 A biomaterial’s ability to resist bacterial adhesion is primarily assessed by:
Biofilm formation assay
Thermal conductivity test
Water vapor transmission test
Mechanical fatigue test
Explanation - Biofilm assays measure bacterial colonization on surfaces, indicating antibacterial properties.
Correct answer is: Biofilm formation assay
Q.15 Which measurement provides the roughness average (Ra) value of a surface?
Atomic force microscopy
Profilometer
Dynamic light scattering
Spectrophotometry
Explanation - A profilometer scans the surface to calculate Ra, the average roughness.
Correct answer is: Profilometer
Q.16 The term 'biodegradation rate' refers to:
The speed at which a material is metabolized by organisms
The electrical breakdown of a polymer
The rate of polymer chain scission in vacuum
The rate of hydrolysis in an acidic medium
Explanation - Biodegradation rate is the rate at which living organisms break down a material.
Correct answer is: The speed at which a material is metabolized by organisms
Q.17 Which of the following is a characteristic of a porous biomaterial scaffold?
High mechanical stiffness
Low interconnectivity
High pore interconnectivity
Smooth surface
Explanation - Porosity with interconnected pores allows cell migration and nutrient transport.
Correct answer is: High pore interconnectivity
Q.18 Dynamic mechanical analysis (DMA) measures the viscoelastic response of a material under:
Varying temperature or strain
Constant pressure
Ultraviolet light exposure
High humidity conditions
Explanation - DMA applies oscillatory stress/strain while changing temperature to assess storage and loss moduli.
Correct answer is: Varying temperature or strain
Q.19 The 'S' value in the context of bioresorbable polymers refers to:
Solubility index
Swelling ratio
Surface area
Strength parameter
Explanation - The S value indicates how rapidly a polymer dissolves in aqueous environments.
Correct answer is: Solubility index
Q.20 Which technique would you use to analyze the chemical composition of a biomaterial surface at the atomic level?
XPS (X-ray photoelectron spectroscopy)
SEM (Scanning electron microscopy)
TGA (Thermogravimetric analysis)
Nanoindentation
Explanation - XPS probes elemental composition and chemical states near the surface (~10 nm depth).
Correct answer is: XPS (X-ray photoelectron spectroscopy)
Q.21 Which of the following is an example of a 'soft' biomaterial?
Polyethylene
Polyurethane
Hydrogel
Titanium alloy
Explanation - Hydrogels are soft, water‑rich materials often used for tissue engineering.
Correct answer is: Hydrogel
Q.22 In a cell culture experiment, the term 'MTT assay' refers to:
Measurement of mitochondrial activity
Measurement of protein concentration
Measurement of DNA fragmentation
Measurement of cell adhesion strength
Explanation - MTT is reduced by mitochondrial dehydrogenases in viable cells, producing a measurable color change.
Correct answer is: Measurement of mitochondrial activity
Q.23 What is the main purpose of sterilization of biomaterials before implantation?
To increase tensile strength
To remove contaminants and microbes
To enhance electrical conductivity
To lower surface roughness
Explanation - Sterilization eliminates pathogens that could cause infection after implantation.
Correct answer is: To remove contaminants and microbes
Q.24 Which imaging technique provides high‑resolution images of cellular interactions with a scaffold?
Confocal microscopy
Micro‑CT
X‑ray diffraction
Dynamic light scattering
Explanation - Confocal microscopy allows 3D imaging of fluorescently labeled cells in a scaffold.
Correct answer is: Confocal microscopy
Q.25 A polymer with a glass transition temperature (Tg) above body temperature is:
In a rubbery state at 37°C
In a glassy state at 37°C
Completely soluble in water
Biodegradable immediately
Explanation - If Tg > 37°C, the polymer remains glassy (rigid) at body temperature.
Correct answer is: In a glassy state at 37°C
Q.26 Which parameter is most relevant for evaluating the suitability of a polymeric implant for load‑bearing applications?
Young's modulus
Water uptake ratio
Surface roughness
Degree of crystallinity
Explanation - Young's modulus reflects stiffness, critical for load‑bearing implants.
Correct answer is: Young's modulus
Q.27 In the context of biomaterials, the 'n' in a diffusion equation typically refers to:
Number of molecules released per second
Order of the reaction
Exponent indicating diffusion type
Surface charge density
Explanation - The exponent 'n' determines if diffusion is Fickian, anomalous, etc.
Correct answer is: Exponent indicating diffusion type
Q.28 What does the term 'pore size distribution' describe?
Variations in pore size throughout a scaffold
Average pore size only
Electrical resistance of pores
Surface area of pores
Explanation - Pore size distribution characterizes how pore sizes vary, influencing cell migration.
Correct answer is: Variations in pore size throughout a scaffold
Q.29 Which method would best quantify the total protein adsorption on a biomaterial surface?
BCA assay
XPS
Thermogravimetics
Nanoindentation
Explanation - BCA assay measures protein concentration, useful for assessing adsorption.
Correct answer is: BCA assay
Q.30 The 'critical pore size' for bone ingrowth is approximately:
0.5–1 µm
10–100 µm
200–300 µm
1–2 mm
Explanation - Bone cells require pores in the 10–100 µm range for optimal ingrowth.
Correct answer is: 10–100 µm
Q.31 Which test measures the rate of gas evolution from a material under acidic conditions?
Acidic degradation test
Hydrogen evolution test
TGA
SEM
Explanation - Hydrogen evolution quantifies gas release, indicating acid‑sensitive degradation.
Correct answer is: Hydrogen evolution test
Q.32 In a cell viability assay, a lower absorbance reading indicates:
Higher cell proliferation
Higher cytotoxicity
No effect
Increased metabolic rate
Explanation - Lower absorbance means fewer viable cells, indicating cytotoxic effects.
Correct answer is: Higher cytotoxicity
Q.33 Which property is directly measured by the 'elastic modulus' obtained from compression tests?
Elasticity under compressive load
Shear strength
Surface roughness
Electrical resistivity
Explanation - Elastic modulus quantifies material stiffness when compressed.
Correct answer is: Elasticity under compressive load
Q.34 A biomaterial that releases a therapeutic drug over a period of weeks is considered a:
Drug‑eluting implant
Bioactive glass
Conductive polymer
Hydrogel
Explanation - Drug‑eluting implants provide controlled drug release.
Correct answer is: Drug‑eluting implant
Q.35 Which spectroscopic technique is best for identifying functional groups in a polymer?
FTIR
NMR
XRD
UV‑Vis
Explanation - FTIR detects characteristic vibrational frequencies of functional groups.
Correct answer is: FTIR
Q.36 What does a high coefficient of friction (COF) imply about a biomaterial surface?
It is slippery
It is rough and resistant to sliding
It has high wettability
It is highly elastic
Explanation - Higher COF means more resistance to motion over the surface.
Correct answer is: It is rough and resistant to sliding
Q.37 The term 'biointegration' refers to:
The incorporation of a biomaterial into a living tissue
The sterilization of a biomaterial
The breakdown of a biomaterial by enzymes
The electrical integration of a sensor
Explanation - Biointegration is the process where tissue grows into or onto the implant.
Correct answer is: The incorporation of a biomaterial into a living tissue
Q.38 Which of the following is a non‑contact method to measure surface topography?
Laser profilometry
Profilometer
Nanoindentation
SEM
Explanation - Laser profilometry scans surface height with a laser beam without touching the sample.
Correct answer is: Laser profilometry
Q.39 What is the purpose of using a 'blank' sample in an ELISA assay?
To calibrate the pH meter
To determine background signal
To test the antibody’s specificity
To measure the sample’s viscosity
Explanation - A blank contains all reagents but no analyte, indicating nonspecific background.
Correct answer is: To determine background signal
Q.40 Which analysis provides the molecular weight distribution of a polymer?
Gel permeation chromatography (GPC)
XPS
SEM
Raman spectroscopy
Explanation - GPC separates molecules by size, revealing weight distribution.
Correct answer is: Gel permeation chromatography (GPC)
Q.41 A material with a high water vapor transmission rate (WVTR) is considered:
Impermeable
Highly breathable
Highly hydrophobic
Electrically conductive
Explanation - High WVTR means moisture can easily pass through the material.
Correct answer is: Highly breathable
Q.42 Which technique would you use to identify crystalline phases in a ceramic scaffold?
XRD
TGA
MALDI‑TOF
UV‑Vis
Explanation - XRD detects specific diffraction peaks of crystalline phases.
Correct answer is: XRD
Q.43 The 'Sanchez–O'Rourke model' is used to analyze:
Porosity of a scaffold
Permeability of a composite
Fatigue life of metals
Drug release kinetics
Explanation - It provides an equation linking porosity and pore size distribution.
Correct answer is: Porosity of a scaffold
Q.44 Which of the following is not a typical parameter measured during a swelling test?
Weight gain
Swelling ratio
Surface roughness
Time to equilibrium
Explanation - Swelling tests focus on weight and dimensions; roughness is unrelated.
Correct answer is: Surface roughness
Q.45 A scaffold’s porosity is 80%. What does this imply?
80% of the scaffold is solid
20% of the scaffold is solid
80% of the scaffold is empty space
The scaffold contains 80% water
Explanation - Porosity is the fraction of volume that is void.
Correct answer is: 80% of the scaffold is empty space
Q.46 Which imaging technique provides sub‑nanometer resolution of crystalline structures?
Transmission electron microscopy (TEM)
XRD
Confocal microscopy
DLS
Explanation - TEM can image lattice fringes at sub‑nanometer resolution.
Correct answer is: Transmission electron microscopy (TEM)
Q.47 In a hydrogel degradation study, a sudden drop in mass indicates:
Swelling
Crystallization
Bulk erosion
Surface erosion
Explanation - Bulk erosion removes material uniformly, causing rapid mass loss.
Correct answer is: Bulk erosion
Q.48 What does the 'n' value of 0.5 in a drug release kinetics model suggest?
Zero‑order release
First‑order release
Fickian diffusion
Anomalous transport
Explanation - An 'n' of 0.5 in Higuchi model indicates classic Fickian diffusion.
Correct answer is: Fickian diffusion
Q.49 Which of the following is a key factor determining the biocompatibility of a material?
Color
Density
Surface chemistry
Shape
Explanation - Surface chemistry influences protein adsorption and cell interaction.
Correct answer is: Surface chemistry
Q.50 What is the primary goal of a 'degradation profile' in biomaterial testing?
To determine the color change over time
To quantify mass loss versus time
To measure electrical conductivity
To assess surface roughness
Explanation - A degradation profile tracks how mass decreases as the material breaks down.
Correct answer is: To quantify mass loss versus time
Q.51 Which technique is suitable for measuring the zeta potential of nanoparticles?
Dynamic light scattering (DLS)
Microelectrophoresis
SEM
XRD
Explanation - Microelectrophoresis measures the electrophoretic mobility, from which zeta potential is calculated.
Correct answer is: Microelectrophoresis
Q.52 Why is a 'sterile' biomaterial required for in‑vivo studies?
To avoid chemical contamination
To prevent infection
To maintain mechanical strength
To reduce degradation rate
Explanation - Sterility eliminates microbes that could infect the test subject.
Correct answer is: To prevent infection
Q.53 Which parameter is NOT directly obtained from a stress‑strain curve?
Yield strength
Young's modulus
Hardness
Elongation at break
Explanation - Hardness requires indentation tests, not stress‑strain data.
Correct answer is: Hardness
Q.54 In a water uptake test, what does an initial rapid weight gain followed by plateau indicate?
Sorption is limited by pore size
Complete dissolution
Surface contamination
Thermal expansion
Explanation - Rapid initial absorption fills pores; the plateau indicates equilibrium.
Correct answer is: Sorption is limited by pore size
Q.55 Which of these tests measures a material’s resistance to chemical attack?
Salt spray test
Water absorption test
Hardness test
Dynamic mechanical analysis
Explanation - A salt spray chamber evaluates corrosion resistance.
Correct answer is: Salt spray test
Q.56 What does 'pH drift' indicate in a buffer solution during a biocompatibility test?
Rapid dissolution
Stable environment
Presence of ions
Temperature fluctuations
Explanation - Ion release from a material can shift the pH of the surrounding buffer.
Correct answer is: Presence of ions
Q.57 Which of the following is a key indicator of a hydrogel’s 'swelling ratio'?
Mass gain after immersion
Electrical conductivity
Surface roughness
Hardness
Explanation - Swelling ratio is calculated from weight before and after water absorption.
Correct answer is: Mass gain after immersion
Q.58 Which test determines the crystallinity percentage of a polymer?
XRD
TGA
FTIR
UV‑Vis
Explanation - XRD peak areas correspond to crystalline and amorphous contributions.
Correct answer is: XRD
Q.59 The 'contact angle' of 90° indicates:
Hydrophilic surface
Hydrophobic surface
Perfectly wetting surface
Neutral wetting characteristic
Explanation - A 90° angle suggests equal affinity for liquid and solid surfaces.
Correct answer is: Neutral wetting characteristic
Q.60 In a fatigue test, the S–N curve represents:
Stress vs. number of cycles
Strain vs. temperature
Speed vs. time
Stress vs. strain
Explanation - S–N curves plot applied stress against cycles to failure for fatigue analysis.
Correct answer is: Stress vs. number of cycles
Q.61 What is the typical purpose of a 'control' sample in a biocompatibility assay?
To provide a baseline for comparison
To increase sample size
To sterilize the material
To calibrate instruments
Explanation - Controls establish the expected response without the test material.
Correct answer is: To provide a baseline for comparison
Q.62 Which of the following materials is commonly used as a 3D printing bioink?
Polylactic acid (PLA)
Polydimethylsiloxane (PDMS)
Alginate
Copper
Explanation - Alginate forms hydrogels cross‑linked with calcium, suitable for bioink.
Correct answer is: Alginate
Q.63 Which test is used to measure the adhesion of cells to a biomaterial surface?
Cell adhesion assay
XRD
TGA
SEM
Explanation - Adhesion assays count cells that remain attached after washing steps.
Correct answer is: Cell adhesion assay
Q.64 Why is 'surface roughness' important in implant design?
It affects optical clarity
It influences cell attachment
It changes electrical conductivity
It reduces density
Explanation - Surface roughness can promote or inhibit cell adhesion and proliferation.
Correct answer is: It influences cell attachment
Q.65 The 'Young's modulus' of a material is measured in:
Newton/meter
Pascal
Volts
Watt
Explanation - Young's modulus is stress over strain, giving units of pressure (Pa).
Correct answer is: Pascal
Q.66 Which of the following describes a 'hydrophilic' polymer?
It repels water
It absorbs water readily
It is electrically conductive
It is brittle
Explanation - Hydrophilic polymers attract water molecules, leading to swelling.
Correct answer is: It absorbs water readily
Q.67 A scaffold with a pore interconnectivity of 90% will:
Allow limited cell migration
Enable extensive cell migration and nutrient flow
Prevent cell attachment
Increase stiffness dramatically
Explanation - High interconnectivity supports tissue ingrowth and vascularization.
Correct answer is: Enable extensive cell migration and nutrient flow
Q.68 Which property is NOT determined by the glass transition temperature (Tg)?
Stiffness at 37°C
Thermal stability
Mechanical damping
Electrical conductivity
Explanation - Tg influences mechanical behavior, not electrical conductivity.
Correct answer is: Electrical conductivity
Q.69 Which analytical technique measures the elemental composition up to 100 nm below the surface?
XPS
SEM
FTIR
TGA
Explanation - XPS provides elemental analysis of the top few nanometers of a surface.
Correct answer is: XPS
Q.70 In a degradation study, a material’s mass loss curve that shows a linear decrease indicates:
Fickian diffusion
Zero‑order degradation
Surface erosion
Crystallization
Explanation - Linear mass loss suggests a constant degradation rate over time.
Correct answer is: Zero‑order degradation
Q.71 The 'critical micelle concentration (CMC)' refers to:
The concentration at which surfactants form micelles
The concentration of ions in a buffer
The threshold of material swelling
The point of phase transition in polymers
Explanation - CMC is the concentration where surfactant molecules aggregate into micelles.
Correct answer is: The concentration at which surfactants form micelles
Q.72 Which of the following is a direct measure of a polymer’s ability to conduct electricity?
Conductivity test
XRD
TGA
Raman spectroscopy
Explanation - Electrical conductivity is measured using a four‑point probe or similar methods.
Correct answer is: Conductivity test
Q.73 During a mechanical compression test, the material’s stress at 10% strain is called:
Ultimate compressive strength
Yield compressive strength
Modulus of resilience
Fracture toughness
Explanation - Stress at 10% strain often approximates yield stress in compression.
Correct answer is: Yield compressive strength
Q.74 Which surface treatment technique can increase a polymer’s bioactivity?
Plasma oxidation
Laser engraving
Chemical etching
All of the above
Explanation - All listed methods modify surface chemistry or topography, enhancing bioactivity.
Correct answer is: All of the above
Q.75 What does a 'zero‑order' release profile mean in drug delivery?
Rate increases over time
Rate decreases over time
Rate remains constant
Rate varies with temperature
Explanation - Zero‑order release is independent of drug concentration and is constant.
Correct answer is: Rate remains constant
Q.76 Which test would you use to assess the electrical impedance of a biomaterial?
Electrochemical impedance spectroscopy (EIS)
TGA
FTIR
SEM
Explanation - EIS measures impedance over a range of frequencies.
Correct answer is: Electrochemical impedance spectroscopy (EIS)
Q.77 During a 'Swelling test', the initial water uptake is typically measured at:
Time zero
After 24 hours
After 7 days
After 1 month
Explanation - The initial uptake gives a baseline for subsequent swelling measurements.
Correct answer is: Time zero
Q.78 In a cell viability test, the term 'IC50' refers to:
50% cell attachment
50% inhibitory concentration of a toxin
50% cell migration
50% degradation rate
Explanation - IC50 is the concentration that reduces cell viability by 50%.
Correct answer is: 50% inhibitory concentration of a toxin
Q.79 Which of the following is a key factor in designing a biodegradable polymer for bone tissue engineering?
High electrical conductivity
Controlled degradation rate
High thermal stability
Low porosity
Explanation - Degradation must match new tissue formation for effective bone regeneration.
Correct answer is: Controlled degradation rate
Q.80 The 'pore size distribution' in a scaffold is determined by:
SEM imaging
µCT reconstruction
TGA analysis
XRD pattern
Explanation - µCT provides 3D data to analyze pore size variations across the scaffold.
Correct answer is: µCT reconstruction
Q.81 In a 'cell spreading assay', which parameter is typically measured?
Cell area
Surface roughness
Electrical conductivity
Water uptake
Explanation - Cell spreading is quantified by the area covered on the surface.
Correct answer is: Cell area
Q.82 Which of the following is not a type of bioresorbable polymer?
Poly(lactic-co-glycolic acid) (PLGA)
Poly(ethylene terephthalate) (PET)
Polycaprolactone (PCL)
Polylactic acid (PLA)
Explanation - PET is non‑biodegradable and not commonly used for resorbable implants.
Correct answer is: Poly(ethylene terephthalate) (PET)
Q.83 A 'contact angle' measurement of 0° indicates:
Hydrophobic surface
Hydrophilic surface
Neutral wetting
Non‑wetting surface
Explanation - A droplet spreads completely, showing high wettability.
Correct answer is: Hydrophilic surface
Q.84 Which analytical technique is best suited to identify the degree of crystallinity in a polymer?
XRD
FTIR
SEM
DLS
Explanation - XRD provides crystalline peaks that can be quantified for crystallinity.
Correct answer is: XRD
Q.85 What does the term 'bioinert' refer to a material’s property?
It actively promotes tissue growth
It is resistant to degradation
It does not provoke an immune response
It conducts electricity
Explanation - Bioinert materials are biologically passive, causing minimal response.
Correct answer is: It does not provoke an immune response
Q.86 Which property is directly measured by a 'four‑point probe'?
Electrical resistivity
Surface roughness
Mechanical strength
Swelling ratio
Explanation - The four‑point probe determines resistivity or conductivity of a material.
Correct answer is: Electrical resistivity
Q.87 In a 'biodegradation' experiment, why is the pH of the medium monitored?
To check for temperature changes
To detect changes caused by material degradation
To measure electrical conductivity
To ensure no contamination
Explanation - Degradation can release acidic or basic products, shifting pH.
Correct answer is: To detect changes caused by material degradation
Q.88 Which of the following is a typical application of a 'hydrogel'?
Electrical wiring
Drug delivery
Structural support in buildings
Data storage
Explanation - Hydrogels can release drugs slowly by swelling and diffusion.
Correct answer is: Drug delivery
Q.89 Which technique can be used to assess the 'surface energy' of a biomaterial?
Contact angle measurement
SEM
TGA
XRD
Explanation - Contact angle data is used to calculate surface energy via Owens–Wendt method.
Correct answer is: Contact angle measurement
Q.90 A scaffold with a 'high porosity' but low mechanical strength is best suited for:
Load‑bearing bone implants
Soft tissue engineering
Electrical components
Corrosion studies
Explanation - Soft tissues don't require high load capacity; porosity promotes cell growth.
Correct answer is: Soft tissue engineering
Q.91 The 'Swelling Ratio' of a hydrogel is calculated by:
(W2 - W1) / W1
W1 / W2
W2 / W1
(W1 + W2) / 2
Explanation - Swelling Ratio = (wet weight – dry weight) ÷ dry weight.
Correct answer is: (W2 - W1) / W1
Q.92 What is the purpose of a 'drying step' before a TGA test?
Remove surface contaminants
Evaporate absorbed water
Cool the sample
Increase sample mass
Explanation - Removing water ensures weight loss reflects thermal degradation only.
Correct answer is: Evaporate absorbed water
Q.93 Which of the following best describes a 'biocompatible coating' on a metal implant?
It degrades in body fluid
It encourages corrosion
It promotes cell adhesion
It reduces mechanical strength
Explanation - Coatings improve compatibility by supporting cell attachment and growth.
Correct answer is: It promotes cell adhesion
Q.94 What is the key advantage of 'electrospinning' in biomaterial fabrication?
Produces large porous blocks
Creates nanofibrous mats resembling extracellular matrix
Enhances electrical conductivity
Reduces degradation rate
Explanation - Electrospun fibers mimic ECM architecture for cell attachment.
Correct answer is: Creates nanofibrous mats resembling extracellular matrix
Q.95 In a 'water vapor transmission rate (WVTR)' test, a higher WVTR indicates:
Lower moisture permeability
Higher moisture permeability
Higher thermal conductivity
Lower electrical resistance
Explanation - WVTR quantifies how quickly water vapor passes through a material.
Correct answer is: Higher moisture permeability
Q.96 The 'Young's modulus' is the slope of the:
Stress‑strain curve in the elastic region
Strain‑time curve
Stress‑temperature curve
Stress‑frequency curve
Explanation - Young's modulus is calculated from the initial linear part of stress–strain.
Correct answer is: Stress‑strain curve in the elastic region
Q.97 Which property is most important for a vascular graft material?
High stiffness
Flexibility and biocompatibility
High thermal resistance
Low porosity
Explanation - Blood vessels require flexible, biocompatible materials to accommodate flow.
Correct answer is: Flexibility and biocompatibility
Q.98 During a 'cytotoxicity' test, what does a cell viability of 80% indicate?
Highly toxic material
No toxicity
Moderate toxicity
Complete cell death
Explanation - 80% viability means 20% cell death, indicating some toxicity.
Correct answer is: Moderate toxicity
Q.99 A 'hydroxyapatite coating' on a titanium implant is intended to:
Reduce corrosion
Promote bone bonding
Increase electrical conductivity
Degrade rapidly
Explanation - Hydroxyapatite is bioactive and supports osteointegration.
Correct answer is: Promote bone bonding
Q.100 Which of the following is a disadvantage of 'highly porous' scaffolds?
Increased mechanical strength
Reduced nutrient diffusion
Lower cell adhesion
Higher degradation rate
Explanation - Very high porosity can decrease the available surface for cell attachment.
Correct answer is: Lower cell adhesion
Q.101 The 'critical micelle concentration (CMC)' is relevant to which of these biomaterial processes?
Drug encapsulation in micelles
Hydrogel cross‑linking
Surface roughness measurement
Mechanical testing
Explanation - Below CMC surfactants are monomeric; above CMC form micelles for drug delivery.
Correct answer is: Drug encapsulation in micelles
Q.102 Which test is used to evaluate the 'sterility' of a biomaterial?
Microbial culture assay
TGA
SEM
XPS
Explanation - Microbial cultures detect viable bacteria or fungi on a material surface.
Correct answer is: Microbial culture assay
Q.103 Which imaging method is best for visualizing live cells within a 3D scaffold?
Confocal microscopy
SEM
XRD
TGA
Explanation - Confocal allows optical sectioning of fluorescent cells inside scaffolds.
Correct answer is: Confocal microscopy
Q.104 What does a 'contact angle of 120°' signify about a surface?
Hydrophilic surface
Hydrophobic surface
Neutral wetting
No interaction with water
Explanation - Large contact angles indicate poor wetting and hydrophobicity.
Correct answer is: Hydrophobic surface
Q.105 Which parameter is not directly obtained from a 'Nanoindentation' test?
Hardness
Young's modulus
Surface roughness
Depth of indentation
Explanation - Nanoindentation measures hardness and modulus; roughness requires separate tools.
Correct answer is: Surface roughness
Q.106 Which property is most critical for a 'contact lens' material?
High stiffness
Excellent oxygen permeability
High electrical conductivity
Strong adhesion to bone
Explanation - Contact lenses must allow oxygen to reach the cornea.
Correct answer is: Excellent oxygen permeability
Q.107 The 'Fourier‑Transform Infrared Spectroscopy (FTIR)' can identify which of the following?
Crystal lattice planes
Elemental composition
Functional groups
Electrical impedance
Explanation - FTIR detects characteristic vibrational frequencies of chemical bonds.
Correct answer is: Functional groups
Q.108 Which of the following is a characteristic of a 'biodegradable polymer'?
Non‑degradable under physiological conditions
Slowly degrades into non‑toxic products
Highly conductive
Impenetrable to water
Explanation - Biodegradable polymers break down into harmless molecules in the body.
Correct answer is: Slowly degrades into non‑toxic products
Q.109 What does 'surface energy' influence in biomaterial design?
Electrical conductivity
Cell adhesion and protein adsorption
Thermal expansion
Mechanical strength
Explanation - Higher surface energy generally improves protein adsorption and cell attachment.
Correct answer is: Cell adhesion and protein adsorption
Q.110 In a 'degradation study', the term 'elimination half‑life' refers to:
Time for half of the mass to degrade
Time for half of the drug to be released
Time to reach equilibrium
Time for polymer chains to break
Explanation - Half‑life measures the time required for 50% mass loss.
Correct answer is: Time for half of the mass to degrade
Q.111 Which of the following tests measures the 'elastic limit' of a polymer?
Tensile test
Hardness test
Contact angle measurement
XPS
Explanation - Tensile testing provides the stress at which elastic behavior ends.
Correct answer is: Tensile test
Q.112 Which material property is measured by the 'Raman shift' peaks?
Chemical composition
Mechanical strength
Surface roughness
Electrical resistivity
Explanation - Raman shifts correspond to vibrational modes, indicating chemical structure.
Correct answer is: Chemical composition
Q.113 The 'biological degradation' of a polymer is mainly due to:
Thermal oxidation
Mechanical wear
Enzymatic action
UV exposure
Explanation - Enzymes in body fluids catalyze bond cleavage in biodegradable polymers.
Correct answer is: Enzymatic action
Q.114 Which of the following best describes 'bioactive glass'?
It is electrically conductive
It can bond to bone and stimulate regeneration
It is highly hydrophobic
It is a polymer
Explanation - Bioactive glass forms a hydroxyapatite layer that bonds to bone tissue.
Correct answer is: It can bond to bone and stimulate regeneration
Q.115 During a 'cell viability' assay using resazurin, a blue solution turns:
Red
Green
Yellow
Orange
Explanation - Resazurin is reduced to resorufin, turning the solution from blue to green.
Correct answer is: Green
Q.116 Which test would be most appropriate to measure the 'water vapor permeability' of a polymeric membrane?
Dew point measurement
Water vapor transmission rate (WVTR) test
FTIR
SEM
Explanation - WVTR directly quantifies how much moisture passes through a material.
Correct answer is: Water vapor transmission rate (WVTR) test
Q.117 What is the main purpose of 'surface modification' with polydopamine on a titanium implant?
Increase electrical conductivity
Improve hydrophilicity and protein adsorption
Make the surface hydrophobic
Decrease mechanical strength
Explanation - Polydopamine creates a bioinspired layer that enhances cell interaction.
Correct answer is: Improve hydrophilicity and protein adsorption
Q.118 Which of the following is NOT a typical analysis performed on a drug‑eluting implant?
Release kinetics
Mechanical strength
Surface roughness
Electrical conductivity
Explanation - Drug‑eluting implants usually focus on release, mechanics, and surface properties.
Correct answer is: Electrical conductivity
Q.119 In a 'porosity' test using mercury intrusion porosimetry, mercury is forced into pores of the scaffold. A higher intrusion pressure indicates:
Larger pores
Smaller pores
Higher surface area
Greater crystallinity
Explanation - Smaller pores require higher pressure to penetrate mercury.
Correct answer is: Smaller pores
Q.120 Which property is measured by a 'bacterial adhesion test'?
The number of bacteria attached to a surface
The tensile strength of the material
The thermal expansion coefficient
The contact angle
Explanation - Bacterial adhesion tests quantify microbial attachment to biomaterial surfaces.
Correct answer is: The number of bacteria attached to a surface
Q.121 Which of the following best describes a 'hydrogel'?
A dense, crystalline solid
A soft, water‑rich polymer network
A high‑conductivity metal
A rigid ceramic
Explanation - Hydrogels swell in water but maintain a cross‑linked network.
Correct answer is: A soft, water‑rich polymer network
Q.122 What does the 'contact angle hysteresis' indicate?
Difference between advancing and receding angles
Surface roughness
Electrical conductivity
Chemical composition
Explanation - Hysteresis is the difference between advancing and receding contact angles, related to surface heterogeneity.
Correct answer is: Difference between advancing and receding angles
Q.123 Which technique is used to measure the 'zeta potential' of nanoparticles?
Dynamic light scattering (DLS)
Zeta potential analyzer
SEM
XPS
Explanation - A zeta potential analyzer measures the electrophoretic mobility to calculate surface charge.
Correct answer is: Zeta potential analyzer
Q.124 Which of the following is a primary advantage of using 'PLGA' in drug delivery?
Permanent, non‑degradable matrix
Controlled, adjustable degradation
Electrical conductivity
High thermal stability
Explanation - PLGA degrades to lactic and glycolic acids at tunable rates.
Correct answer is: Controlled, adjustable degradation
Q.125 What does a 'high water uptake ratio' imply about a polymer?
It is hydrophobic
It has many hydrophilic groups
It is electrically conductive
It is rigid
Explanation - High water uptake indicates many polar groups that attract water.
Correct answer is: It has many hydrophilic groups
Q.126 Which of these tests is used to assess 'surface topography'?
Profilometer
TGA
XRD
FTIR
Explanation - Profilometers scan the surface to quantify roughness and texture.
Correct answer is: Profilometer
Q.127 A scaffold with a pore size of 300 µm is best suited for:
Soft tissue engineering
Bone tissue engineering
Neural tissue engineering
Cardiac tissue engineering
Explanation - Bone cells favor pore sizes in the 100–300 µm range.
Correct answer is: Bone tissue engineering
Q.128 In a 'mechanical fatigue test', the 'fatigue limit' refers to:
Maximum stress the material can withstand without fracture
Minimum stress below which material will not fail in a given number of cycles
Maximum strain before yielding
Maximum temperature the material can endure
Explanation - The fatigue limit is the stress threshold below which fatigue failure is avoided.
Correct answer is: Minimum stress below which material will not fail in a given number of cycles
Q.129 Which method is most suitable for analyzing the 'molecular weight distribution' of a polymer?
Gel permeation chromatography (GPC)
SEM
FTIR
XPS
Explanation - GPC separates molecules by size, giving the molecular weight distribution.
Correct answer is: Gel permeation chromatography (GPC)
Q.130 What does the 'swelling ratio' of a hydrogel depend on?
Cross‑link density and ionic content
Electrical resistance
Surface roughness
Hardness
Explanation - Lower cross‑linking and higher ionic groups increase swelling.
Correct answer is: Cross‑link density and ionic content
Q.131 Which of the following is NOT a typical property evaluated in a 'biodegradable scaffold'?
Degradation rate
Mechanical strength
Electrical conductivity
Biocompatibility
Explanation - Most biodegradable scaffolds are non‑conductive; conductivity is rarely evaluated.
Correct answer is: Electrical conductivity
Q.132 A biomaterial that has a 'contact angle of 85°' is considered:
Hydrophobic
Hydrophilic
Neutral
Superhydrophobic
Explanation - Angles close to 90° suggest near‑neutral wetting.
Correct answer is: Neutral
Q.133 What does the 'contact angle hysteresis' measure?
The difference between advancing and receding angles
The absolute contact angle value
The surface roughness
The hardness of the material
Explanation - Hysteresis indicates energy dissipation due to surface heterogeneity.
Correct answer is: The difference between advancing and receding angles
Q.134 Which analytical method provides a direct measure of 'surface elemental composition' up to ~10 nm depth?
XPS (X‑ray photoelectron spectroscopy)
SEM
TEM
TGA
Explanation - XPS probes the top 10 nm, giving elemental and chemical state information.
Correct answer is: XPS (X‑ray photoelectron spectroscopy)
Q.135 The 'critical pore size' for cell infiltration is typically:
0–5 µm
5–10 µm
10–100 µm
≥1000 µm
Explanation - Cell infiltration usually requires pores between 10–100 µm.
Correct answer is: 10–100 µm
Q.136 Which of the following is a common method to quantify 'protein adsorption' on a biomaterial?
BCA assay
TGA
SEM
XRD
Explanation - BCA measures protein concentration after rinsing the surface.
Correct answer is: BCA assay
Q.137 What is the main benefit of using 'hydroxyapatite' coating on a titanium implant?
Improves electrical conductivity
Promotes bone bonding and integration
Increases corrosion resistance
Enhances thermal conductivity
Explanation - Hydroxyapatite mimics bone mineral, aiding osseointegration.
Correct answer is: Promotes bone bonding and integration
Q.138 A 'biomaterial' that 'degrades in the body' is described as:
Biodegradable
Biostable
Bioactive
Biocompatible
Explanation - Biodegradable materials are designed to be broken down by the body.
Correct answer is: Biodegradable
Q.139 Which test would you use to measure the 'rate of drug release' from a polymeric matrix?
Dialysis method
SEM
TGA
XPS
Explanation - The dialysis method tracks drug concentration in a receiver compartment over time.
Correct answer is: Dialysis method
Q.140 In 'cell culture' studies, the term 'serum-free medium' indicates:
No antibiotics present
No nutrients present
No animal serum present
No growth factors present
Explanation - Serum‑free means the medium lacks animal serum but may contain defined supplements.
Correct answer is: No animal serum present
Q.141 What is the significance of a 'contact angle of 90°' in surface analysis?
Strong hydrophilicity
Strong hydrophobicity
Neutral wettability
Superhydrophobicity
Explanation - An angle near 90° indicates neither hydrophilic nor hydrophobic dominance.
Correct answer is: Neutral wettability
Q.142 Which of the following techniques is used to measure the 'electrical impedance' of a biomaterial?
Electrochemical impedance spectroscopy (EIS)
SEM
XRD
FTIR
Explanation - EIS measures impedance across a frequency range.
Correct answer is: Electrochemical impedance spectroscopy (EIS)
Q.143 A 'hydrogel' typically has a high swelling ratio due to:
Its dense cross‑linked network
Its low water content
Its high ionic groups and hydrophilicity
Its high mechanical strength
Explanation - Hydrogels contain many hydrophilic groups that attract water.
Correct answer is: Its high ionic groups and hydrophilicity
Q.144 Which of the following is NOT a standard test for 'biocompatibility'?
MTT assay
Hemolysis test
Tensile test
Bacterial adhesion test
Explanation - Tensile testing assesses mechanical strength, not direct biocompatibility.
Correct answer is: Tensile test
Q.145 In a 'hydrolysis degradation' study, the weight loss of a polymer is monitored over:
Time only
Time and pH
Temperature only
Light exposure only
Explanation - Hydrolysis depends on time and the pH of the surrounding medium.
Correct answer is: Time and pH
Q.146 A 'porous scaffold' with an interconnectivity of 85% provides:
Limited nutrient transport
High cell infiltration and nutrient transport
Increased mechanical strength
Reduced surface area
Explanation - High interconnectivity facilitates cell migration and fluid flow.
Correct answer is: High cell infiltration and nutrient transport
Q.147 Which test is best for measuring the 'degradation products' of a polymer?
HPLC
SEM
XRD
TGA
Explanation - HPLC can separate and quantify soluble degradation products.
Correct answer is: HPLC
Q.148 Which of the following is a key advantage of a 'nano‑indentation' test?
It measures bulk mechanical properties
It provides localized mechanical data at the nanoscale
It requires large sample sizes
It is destructive to the entire sample
Explanation - Nanoindentation probes mechanical properties in very small volumes.
Correct answer is: It provides localized mechanical data at the nanoscale
Q.149 In a 'cell adhesion' assay, the number of cells attached is usually measured by:
Counting cells after a fluorescent stain
Measuring tensile strength
Analyzing surface roughness
Evaluating electrical impedance
Explanation - Fluorescent labeling allows counting of adherent cells under a microscope.
Correct answer is: Counting cells after a fluorescent stain
Q.150 The 'critical micelle concentration (CMC)' of a surfactant is relevant to:
Polymer cross‑linking
Drug loading in micelles
Surface roughness measurement
Tensile testing
Explanation - Above CMC, surfactants form micelles that can encapsulate drugs.
Correct answer is: Drug loading in micelles
Q.151 Which of these properties is NOT directly related to a polymer’s 'glass transition temperature (Tg)'?
Mechanical stiffness at body temperature
Viscoelastic behavior
Crystallinity
Thermal expansion
Explanation - Tg is a glassy–rubbery transition, not directly tied to crystalline content.
Correct answer is: Crystallinity
Q.152 Which of the following is an example of a 'bioactive ceramic' used in bone regeneration?
Poly(lactic acid)
Hydroxyapatite
Polydimethylsiloxane (PDMS)
Polyethylene
Explanation - Hydroxyapatite is a bioactive ceramic that integrates with bone.
Correct answer is: Hydroxyapatite
Q.153 A 'biodegradable scaffold' with a 'high degradation rate' is suitable for:
Permanent load‑bearing implants
Temporary drug delivery
Long‑term tissue support
Electrical components
Explanation - Rapid degradation matches short‑term drug release applications.
Correct answer is: Temporary drug delivery
Q.154 Which technique can be used to evaluate the 'ionic conductivity' of a polymer electrolyte?
EIS (Electrochemical impedance spectroscopy)
SEM
XRD
TGA
Explanation - EIS provides ionic conductivity by measuring impedance over frequency.
Correct answer is: EIS (Electrochemical impedance spectroscopy)
Q.155 A 'contact angle of 150°' indicates a surface that is:
Highly hydrophilic
Moderately hydrophilic
Neutral
Superhydrophobic
Explanation - Angles above 150° are characteristic of superhydrophobic surfaces.
Correct answer is: Superhydrophobic
Q.156 In a 'biocompatibility' study, the 'hemolysis test' measures:
Cell viability in culture
Blood clot formation
Red blood cell rupture
Platelet adhesion
Explanation - Hemolysis test quantifies how much hemoglobin is released from red cells.
Correct answer is: Red blood cell rupture
Q.157 What does a 'zero‑order release profile' mean for a drug‑eluting implant?
Release rate decreases over time
Release rate increases over time
Release rate remains constant
Release rate is dependent on drug concentration
Explanation - Zero‑order means a constant rate independent of concentration.
Correct answer is: Release rate remains constant
Q.158 Which of the following is a common method to assess 'mechanical fatigue' in polymeric scaffolds?
S‑N curve plotting
TGA
FTIR
SEM
Explanation - S‑N curves relate applied stress to the number of cycles to failure.
Correct answer is: S‑N curve plotting
Q.159 A scaffold’s 'pore size distribution' can be best visualized by which technique?
Micro‑CT
TGA
XRD
SEM
Explanation - µCT provides 3D reconstructions to analyze pore size and distribution.
Correct answer is: Micro‑CT
Q.160 In a 'contact angle' measurement, the 'advancing angle' is determined by:
Increasing droplet volume until it spreads
Decreasing droplet volume until it retracts
Measuring the droplet after heating
Measuring the droplet after cooling
Explanation - Advancing angle is measured by adding liquid to the droplet.
Correct answer is: Increasing droplet volume until it spreads
Q.161 Which property of a biomaterial is most relevant for a 'soft tissue' application?
High stiffness
High flexibility
High thermal conductivity
High electrical impedance
Explanation - Soft tissues require flexible, compliant materials.
Correct answer is: High flexibility
Q.162 A 'hydrogel' that degrades via hydrolysis typically releases its drug through:
Diffusion only
Controlled degradation and diffusion
Rapid dissolution
Electrochemical processes
Explanation - Drug release often combines diffusion and polymer breakdown.
Correct answer is: Controlled degradation and diffusion
Q.163 The 'contact angle' of a surface is measured using:
A goniometer
An X‑ray diffractometer
A dynamic light scattering instrument
A four‑point probe
Explanation - A goniometer measures the angle between liquid droplet and surface.
Correct answer is: A goniometer
Q.164 Which of the following materials is commonly used as a 'hydrophilic' coating for titanium implants?
Polydopamine
Polystyrene
Polytetrafluoroethylene (PTFE)
Polytetraethylene glycol (PEG)
Explanation - Polydopamine forms a hydrophilic surface layer on metals.
Correct answer is: Polydopamine
Q.165 Which technique is best for determining the 'surface energy' of a biomaterial?
Contact angle measurement
XPS
SEM
TGA
Explanation - Surface energy can be derived from contact angle data.
Correct answer is: Contact angle measurement
Q.166 In an 'MTT assay', what color change indicates high cell viability?
Blue to red
Blue to green
Blue to purple
Blue to orange
Explanation - Live cells reduce MTT to a green‑yellow product.
Correct answer is: Blue to green
Q.167 A biomaterial that is designed to be 'biodegradable' must:
Resist all forms of degradation
Degrade into non‑toxic products in the body
Maintain mechanical strength indefinitely
Be electrically conductive
Explanation - Biodegradable biomaterials break down into harmless by‑products.
Correct answer is: Degrade into non‑toxic products in the body
Q.168 The 'TGA' curve typically shows an initial weight loss due to:
Moisture evaporation
Polymer chain scission
Crystal melting
Oxidation of surface
Explanation - Early TGA weight loss is often due to lost moisture.
Correct answer is: Moisture evaporation
Q.169 Which test measures the 'softening point' of a polymeric material?
TGA
DSC (Differential scanning calorimetry)
XRD
FTIR
Explanation - DSC identifies the glass transition and melting temperatures.
Correct answer is: DSC (Differential scanning calorimetry)
Q.170 A 'hydrogel' that swells to 5 times its dry weight is said to have:
Low swelling ratio
Moderate swelling ratio
High swelling ratio
No swelling
Explanation - Swelling ratios above 3–4 times dry weight are considered high.
Correct answer is: High swelling ratio
Q.171 Which property is crucial for a 'vascular graft' material?
High stiffness
Elasticity and flexibility
High thermal resistance
Electrical conductivity
Explanation - Vascular grafts must conform to dynamic blood flow without kinking.
Correct answer is: Elasticity and flexibility
Q.172 The 'critical micelle concentration (CMC)' is the point where:
Surfactants form micelles
Polymers cross‑link
Hydrogels swell
Electrodes degrade
Explanation - CMC indicates the surfactant concentration above which micelles form.
Correct answer is: Surfactants form micelles
Q.173 Which of these tests would you use to assess a biomaterial’s 'thermal stability'?
TGA
SEM
XPS
MTT assay
Explanation - TGA tracks weight loss with temperature, indicating thermal stability.
Correct answer is: TGA
Q.174 What is the main difference between 'hydrophobic' and 'hydrophilic' surfaces?
Water contact angle
Electrical conductivity
Mechanical stiffness
Porosity
Explanation - Hydrophobic surfaces have high contact angles; hydrophilic surfaces have low angles.
Correct answer is: Water contact angle
Q.175 Which of the following is a measure of the 'biocompatibility' of a material?
Tensile strength
Cell viability assay
Surface roughness
Electrical impedance
Explanation - Cell viability assays directly evaluate how a material interacts with cells.
Correct answer is: Cell viability assay
Q.176 Which analysis technique provides a detailed view of 'crystalline phases' in a material?
XRD
SEM
FTIR
TGA
Explanation - XRD is the standard for detecting crystalline structures.
Correct answer is: XRD
Q.177 A 'polymer scaffold' with a 'Young's modulus of 0.5 MPa' is considered:
Very stiff
Soft
Hard
Rigid
Explanation - 0.5 MPa is relatively low, indicating a soft material.
Correct answer is: Soft
Q.178 Which method is commonly used to measure the 'zeta potential' of polymeric nanoparticles?
Zeta potential analyzer
Four‑point probe
SEM
XRD
Explanation - A zeta potential analyzer measures electrophoretic mobility to determine charge.
Correct answer is: Zeta potential analyzer
Q.179 Which of the following tests is performed to evaluate a scaffold's 'mechanical fatigue life'?
S‑N curve analysis
TGA
FTIR
XPS
Explanation - S‑N curves plot stress amplitude vs. cycles to failure, indicating fatigue life.
Correct answer is: S‑N curve analysis
Q.180 A biomaterial that is 'hydrophobic' will likely have:
Low contact angle
High contact angle
Neutral contact angle
No contact angle
Explanation - Hydrophobic surfaces repel water, resulting in high contact angles.
Correct answer is: High contact angle
Q.181 The 'pore interconnectivity' of a scaffold is measured using:
µCT reconstruction
TGA
XRD
SEM
Explanation - µCT provides 3D data to calculate how pores are interconnected.
Correct answer is: µCT reconstruction
Q.182 A 'drug‑eluting scaffold' with a 'zero‑order' release rate will release drug at:
A decreasing rate over time
A constant rate over time
An increasing rate over time
A rate dependent on drug concentration
Explanation - Zero‑order means the release is independent of concentration and stays constant.
Correct answer is: A constant rate over time
Q.183 Which of these methods can determine the 'surface roughness' of a biomaterial?
AFM
TGA
XRD
FTIR
Explanation - AFM scans the surface topography at the nanoscale, measuring roughness.
Correct answer is: AFM
Q.184 The 'critical micelle concentration (CMC)' is important for:
Polymer cross‑linking
Drug encapsulation in micelles
Mechanical strength testing
Thermal analysis
Explanation - Surfactants above the CMC form micelles that can carry drugs.
Correct answer is: Drug encapsulation in micelles
Q.185 Which property is directly related to a biomaterial’s ability to absorb water?
Swelling ratio
Young's modulus
Electrical conductivity
Surface roughness
Explanation - The swelling ratio quantifies how much water the material absorbs.
Correct answer is: Swelling ratio
Q.186 Which of the following is a typical 'biomaterial' used in soft tissue engineering?
Polyethylene
Hydrogel
Titanium alloy
Ceramic
Explanation - Hydrogels mimic soft tissue mechanics and support cell growth.
Correct answer is: Hydrogel
Q.187 The 'contact angle' of a surface is a measure of:
Surface roughness
Surface wettability
Electrical conductivity
Mechanical stiffness
Explanation - The contact angle indicates how a liquid droplet interacts with a surface.
Correct answer is: Surface wettability
Q.188 Which test can be used to measure the 'viscoelasticity' of a polymer?
Dynamic mechanical analysis (DMA)
TGA
XRD
SEM
Explanation - DMA applies oscillatory stress to study viscoelastic behavior.
Correct answer is: Dynamic mechanical analysis (DMA)
Q.189 The 'critical pore size' for bone cell infiltration is typically around:
5–10 µm
10–100 µm
100–200 µm
≥500 µm
Explanation - Bone cells require pores in the 10–100 µm range for effective migration.
Correct answer is: 10–100 µm
Q.190 In an 'MTT assay', the amount of formazan produced is directly proportional to:
The number of live cells
The amount of dead cells
The surface roughness
The water uptake ratio
Explanation - Live cells reduce MTT to formazan; more cells produce more color.
Correct answer is: The number of live cells
Q.191 Which of the following tests measures the 'elastic modulus' of a polymer?
Nanoindentation
TGA
XPS
FTIR
Explanation - Nanoindentation provides localized modulus by measuring force vs. displacement.
Correct answer is: Nanoindentation