Q.1 Which of the following is a systematic error?
Parallax error in reading a scale
Fluctuation in room temperature affecting readings
Random fluctuations in voltmeter readings
Noise in electronic measurements
Explanation - Systematic errors are reproducible and affect the accuracy of measurements consistently, such as parallax error when reading a scale incorrectly.
Correct answer is: Parallax error in reading a scale
Q.2 The precision of an instrument is related to:
Accuracy
Repeatability
Systematic error
Both accuracy and error
Explanation - Precision refers to the closeness of repeated measurements, which is related to the repeatability of the instrument.
Correct answer is: Repeatability
Q.3 The least count of a vernier caliper is 0.01 cm. If a length is measured as 2.34 cm, the absolute error is:
±0.01 cm
±0.005 cm
±0.1 cm
±0.02 cm
Explanation - Absolute error is usually equal to the least count of the measuring instrument, which is ±0.01 cm for the vernier caliper.
Correct answer is: ±0.01 cm
Q.4 Random errors can be reduced by:
Calibration of instruments
Taking multiple readings and averaging
Using a more sensitive instrument
Using correct formula
Explanation - Random errors cause scatter in readings and can be minimized by taking repeated measurements and averaging.
Correct answer is: Taking multiple readings and averaging
Q.5 Which of the following best describes systematic errors?
Errors that occur randomly
Errors due to inherent flaws in the instrument
Errors due to human estimation
Errors that disappear on repeated trials
Explanation - Systematic errors arise due to flaws in the instrument or method and consistently affect the measurements.
Correct answer is: Errors due to inherent flaws in the instrument
Q.6 If the vernier caliper has a main scale of 1 mm division and 50 vernier divisions match 49 main scale divisions, the least count is:
0.02 mm
0.01 mm
0.05 mm
0.1 mm
Explanation - Least count = 1 MSD – 1 VSD = 1 mm – (49/50) mm = 0.01 mm.
Correct answer is: 0.01 mm
Q.7 Which type of error affects the accuracy but not the precision?
Random error
Systematic error
Instrumental error
Parallax error
Explanation - Systematic errors consistently shift all readings, affecting accuracy but not the repeatability (precision).
Correct answer is: Systematic error
Q.8 The percentage error is given by:
(Absolute error / True value) × 100
(Measured value / True value) × 100
(Random error / Absolute error) × 100
(Least count / Measured value) × 100
Explanation - Percentage error quantifies the relative size of the error compared to the true value, calculated as (Absolute error / True value) × 100.
Correct answer is: (Absolute error / True value) × 100
Q.9 A student measures a current with a meter of ±0.05 A precision. If he repeats it 5 times, the average reduces the random error. This is an example of:
Systematic error
Random error
Instrumental error
Gross error
Explanation - Random errors vary unpredictably, and averaging multiple readings reduces their effect.
Correct answer is: Random error
Q.10 Which of the following errors cannot be eliminated by repeated measurements?
Random errors
Systematic errors
Statistical errors
All of the above
Explanation - Systematic errors are inherent to the method or instrument and cannot be reduced by repetition.
Correct answer is: Systematic errors
Q.11 In a micrometer screw gauge, the least count is defined as:
Pitch × Number of divisions on thimble
Pitch / Number of divisions on thimble
Pitch × 10
Number of divisions on sleeve / Pitch
Explanation - Least count = Pitch / Number of divisions on the circular scale of the thimble.
Correct answer is: Pitch / Number of divisions on thimble
Q.12 If an experiment has a high accuracy but low precision, the data points are:
Scattered around true value
Close together but far from true value
Scattered and far from true value
Close to true value but scattered
Explanation - High accuracy means the average is near true value, low precision means individual readings are scattered.
Correct answer is: Close to true value but scattered
Q.13 A random error in a measurement arises due to:
Instrument defect
Observer bias
Environmental fluctuations
All of the above
Explanation - Random errors are unpredictable and occur due to environmental or uncontrollable factors.
Correct answer is: Environmental fluctuations
Q.14 The standard deviation is used to quantify:
Systematic error
Random error
Least count
Gross error
Explanation - Standard deviation measures the spread of data points and helps quantify random errors.
Correct answer is: Random error
Q.15 Which of the following is a gross error?
Misreading an instrument
Parallax error
Zero error
Environmental error
Explanation - Gross errors occur due to human mistakes, such as misreading or recording data incorrectly.
Correct answer is: Misreading an instrument
Q.16 If a measurement is repeated many times and the mean value remains the same but individual values scatter, which error dominates?
Systematic error
Random error
Instrumental error
Gross error
Explanation - Random errors cause variability in repeated measurements while the mean remains unbiased.
Correct answer is: Random error
Q.17 The zero error of a measuring instrument is:
Difference between true value and measured value when quantity is zero
Difference between measured and average value
Error due to rounding
Instrumental precision
Explanation - Zero error occurs when the instrument does not read zero when the measured quantity is actually zero.
Correct answer is: Difference between true value and measured value when quantity is zero
Q.18 In an experiment, if the percentage error is small, it indicates:
High accuracy
Low accuracy
High precision
High systematic error
Explanation - A small percentage error indicates that the measured value is close to the true value, showing high accuracy.
Correct answer is: High accuracy
Q.19 The main difference between accuracy and precision is:
Accuracy measures closeness to true value, precision measures repeatability
Accuracy measures repeatability, precision measures closeness to true value
Both are same
Accuracy measures systematic error, precision measures random error
Explanation - Accuracy refers to closeness to true value; precision refers to how consistent repeated measurements are.
Correct answer is: Accuracy measures closeness to true value, precision measures repeatability
Q.20 Averaging a large number of observations improves:
Systematic error
Random error
Both systematic and random errors
Instrument least count
Explanation - Averaging reduces the effect of random errors but does not affect systematic errors.
Correct answer is: Random error
Q.21 Calibration of an instrument helps in reducing:
Random error
Systematic error
Gross error
Statistical error
Explanation - Calibration adjusts the instrument to remove or reduce systematic errors.
Correct answer is: Systematic error
Q.22 Which of the following represents relative error?
Absolute error / Measured value
Measured value / True value
True value / Absolute error
Mean value / Standard deviation
Explanation - Relative error is the ratio of absolute error to the measured value, often expressed as a fraction or percentage.
Correct answer is: Absolute error / Measured value
Q.23 The main purpose of performing repeated measurements in an experiment is:
To eliminate systematic errors
To reduce random errors
To increase zero error
To reduce least count
Explanation - Repeating measurements and taking an average reduces the effect of random errors.
Correct answer is: To reduce random errors
Q.24 In an experiment, the accuracy is high but precision is low. How will the measurements appear on a graph?
Clustered together far from true value
Scattered around the true value
Clustered around true value
Randomly scattered far from true value
Explanation - High accuracy and low precision means that readings on average are near true value but individual readings are scattered.
Correct answer is: Scattered around the true value