Q.1 Which of the following is the SI unit of force?
Newton
Dyne
Joule
Watt
Explanation - The SI unit of force is Newton (N), defined as 1 kg·m/s².
Correct answer is: Newton
Q.2 The SI unit of electric current is:
Volt
Ampere
Ohm
Coulomb
Explanation - Electric current is measured in Amperes (A), representing 1 Coulomb of charge passing per second.
Correct answer is: Ampere
Q.3 Which of the following is a derived SI unit?
Meter
Kilogram
Pascal
Second
Explanation - Pascal (Pa) is a derived SI unit for pressure, equal to N/m².
Correct answer is: Pascal
Q.4 The unit of luminous intensity in the SI system is:
Candela
Lumen
Lux
Nit
Explanation - Candela (cd) is the SI unit of luminous intensity, measuring the power emitted by a source in a particular direction.
Correct answer is: Candela
Q.5 Which physical quantity is measured in Joules?
Power
Energy
Force
Pressure
Explanation - Energy and work are measured in Joules (J), where 1 J = 1 N·m.
Correct answer is: Energy
Q.6 1 dyne is equal to how many Newtons?
10⁻⁵ N
10⁻⁴ N
10⁻³ N
10⁻² N
Explanation - 1 dyne = 10⁻⁵ kg·m/s² = 10⁻⁵ N. (Check: 1 N = 10⁵ dynes)
Correct answer is: 10⁻⁴ N
Q.7 The SI unit of frequency is:
Hertz
Second
Cycle
Newton
Explanation - Frequency is measured in Hertz (Hz), defined as cycles per second.
Correct answer is: Hertz
Q.8 The fundamental SI unit of mass is:
Gram
Kilogram
Pound
Ounce
Explanation - The kilogram (kg) is the base SI unit of mass.
Correct answer is: Kilogram
Q.9 Which of the following is not an SI base unit?
Meter
Candela
Liter
Second
Explanation - Liter is not an SI base unit; it is a derived unit of volume (1 L = 10⁻³ m³).
Correct answer is: Liter
Q.10 The SI unit of pressure is:
Pascal
Bar
Atmosphere
Newton
Explanation - Pressure is measured in Pascals (Pa), where 1 Pa = 1 N/m².
Correct answer is: Pascal
Q.11 1 Coulomb is equal to the charge of how many electrons?
6.022 × 10²³
1.6 × 10⁻¹⁹
6.25 × 10¹⁸
9.1 × 10⁻³¹
Explanation - 1 Coulomb = 6.25 × 10¹⁸ electrons (charge of one electron ≈ 1.6 × 10⁻¹⁹ C).
Correct answer is: 6.25 × 10¹⁸
Q.12 The SI unit of capacitance is:
Farad
Henry
Ohm
Tesla
Explanation - Capacitance is measured in Farads (F), defined as 1 Coulomb/Volt.
Correct answer is: Farad
Q.13 Which of the following units is a measure of energy?
Joule
Tesla
Henry
Ampere
Explanation - Energy is measured in Joules (J).
Correct answer is: Joule
Q.14 The unit of electric resistance is:
Volt
Ohm
Ampere
Siemens
Explanation - Resistance is measured in Ohms (Ω), where 1 Ω = 1 V/A.
Correct answer is: Ohm
Q.15 The SI unit of magnetic flux is:
Tesla
Weber
Henry
Ampere
Explanation - Magnetic flux is measured in Webers (Wb), where 1 Wb = 1 T·m².
Correct answer is: Weber
Q.16 The SI unit of temperature is:
Celsius
Kelvin
Fahrenheit
Rankine
Explanation - Kelvin (K) is the SI unit of thermodynamic temperature.
Correct answer is: Kelvin
Q.17 1 Watt is equal to:
1 J/s
1 N·m
1 J·s
1 N/s
Explanation - Power is measured in Watts (W), where 1 W = 1 J/s.
Correct answer is: 1 J/s
Q.18 The SI unit of electric charge is:
Ampere
Coulomb
Volt
Ohm
Explanation - Electric charge is measured in Coulombs (C).
Correct answer is: Coulomb
Q.19 The SI unit of radioactivity is:
Becquerel
Gray
Sievert
Curie
Explanation - Radioactivity is measured in Becquerels (Bq), defined as one decay per second.
Correct answer is: Becquerel
Q.20 The SI unit of angle is:
Degree
Radian
Steradian
Gradian
Explanation - Radian is the SI unit of plane angle, defined as the angle subtended by an arc equal to the radius.
Correct answer is: Radian
Q.21 Which is the SI unit of electric potential?
Volt
Ampere
Ohm
Watt
Explanation - Electric potential difference is measured in Volts (V).
Correct answer is: Volt
Q.22 The SI unit of inductance is:
Henry
Farad
Ohm
Tesla
Explanation - Inductance is measured in Henry (H), where 1 H = 1 Wb/A.
Correct answer is: Henry
Q.23 The SI unit of momentum is:
kg·m/s
N·m
J
kg·m²/s²
Explanation - Momentum = mass × velocity, so its SI unit is kg·m/s.
Correct answer is: kg·m/s
Q.24 The unit of electric conductivity is:
Siemens
Ohm
Farad
Henry
Explanation - Electric conductivity is measured in Siemens (S), reciprocal of resistance.
Correct answer is: Siemens
Q.25 The SI unit of solid angle is:
Radian
Steradian
Degree
Gradian
Explanation - Steradian (sr) is the SI unit of solid angle, defined as the area on a sphere of radius r divided by r².
Correct answer is: Steradian