Physical Quantities and Measurement is the foundation of physics, dealing with quantities that can be measured, their units, and the methods used for accurate measurement. This chapter explains base and derived quantities, the International System of Units (SI), measuring instruments, prefixes, significant figures, scientific notation, and types of errors in measurements. The MCQs below will help students strengthen their understanding of these essential concepts.
1. Which of the following is a base quantity?
- A. Length ✅
- B. Velocity
- C. Force
- D. Energy
Explanation: Length is a base quantity; velocity, force, and energy are derived quantities.
2. The SI unit of electric current is:
- A. Ampere ✅
- B. Coulomb
- C. Volt
- D. Ohm
Explanation: The ampere (A) is the SI base unit for measuring electric current.
3. Which prefix represents 10⁻³?
- A. Milli ✅
- B. Micro
- C. Kilo
- D. Centi
Explanation: Milli (m) means one-thousandth (10⁻³) of a unit.
4. A quantity having magnitude and direction is called:
- A. Vector quantity ✅
- B. Scalar quantity
- C. Base quantity
- D. Derived quantity
Explanation: Vector quantities require both magnitude and direction for complete description.
5. Which of the following is a derived quantity?
- A. Velocity ✅
- B. Length
- C. Mass
- D. Time
Explanation: Velocity is derived from base quantities length and time.
6. The SI unit of force is:
- A. Newton ✅
- B. Joule
- C. Watt
- D. Pascal
Explanation: Force is measured in newtons (N), where 1 N = 1 kg·m/s².
7. Which instrument is used to measure mass in a laboratory?
- A. Beam balance ✅
- B. Vernier caliper
- C. Stopwatch
- D. Thermometer
Explanation: Beam balances measure the mass of objects with high accuracy.
8. Which of the following is NOT an SI base unit?
- A. Liter ✅
- B. Meter
- C. Second
- D. Kelvin
Explanation: Liter is a unit of volume and is not a base SI unit.
9. Which device is used to measure very small lengths accurately?
- A. Vernier caliper ✅
- B. Stopwatch
- C. Spring balance
- D. Thermometer
Explanation: Vernier calipers measure small lengths and diameters precisely.
10. A stopwatch is used to measure:
- A. Time interval ✅
- B. Mass
- C. Length
- D. Temperature
Explanation: Stopwatches are used to measure the time taken for an event or activity.
11. Which of the following is a scalar quantity?
- A. Speed ✅
- B. Velocity
- C. Force
- D. Displacement
Explanation: Scalars have only magnitude; speed does not require direction.
12. An error caused by faulty equipment is called:
- A. Systematic error ✅
- B. Random error
- C. Gross error
- D. Human error
Explanation: Systematic errors occur due to consistent faults in equipment or methods.
13. Which prefix represents 10⁶?
- A. Mega ✅
- B. Giga
- C. Kilo
- D. Centi
Explanation: Mega (M) stands for one million (10⁶) units.
14. The degree of exactness of a measurement is called:
- A. Precision ✅
- B. Accuracy
- C. Sensitivity
- D. Reliability
Explanation: Precision refers to how close repeated measurements are to each other.
15. Which of the following is the SI unit of temperature?
- A. Kelvin ✅
- B. Celsius
- C. Fahrenheit
- D. Joule
Explanation: Kelvin (K) is the SI base unit for measuring temperature.