NEET Physics: Physics and Measurement Practice Questions
13 free multiple-choice questions on Physics and Measurement for NEET Physics, each with the correct answer and a step-by-step explanation. Attempt a question, then reveal the solution to check your reasoning.
Practice thousands more Physics and Measurement questions in the app →Q1. In the SI system, the system of units is based on which set of fundamental quantities?
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Correct answer: A — Length, Mass, and Time
The SI system is built upon seven base quantities: length (meter), mass (kilogram), time (second), electric current (ampere), temperature (kelvin), amount of substance (mole), and luminous intensity (candela).
Q2. The principle of homogeneity of dimensions is applied when:
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Correct answer: A — Checking the dimensional correctness of an equation
The principle of homogeneity states that in an equation, the dimensions of all terms on both sides must be the same. This is used to check dimensional consistency.
Q3. In a calculation involving multiplication of measurements, which of the following statements correctly determines the number of significant figures in the final result? If A = 12.5 mm and B = 2.0 mm, what is the correct number of significant figures for the product P = A × B ?
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Correct answer: A — 2
For multiplication and division, the result must have the same number of significant figures as the measurement with the fewest significant figures. Here, A (12.5) has 3 sig figs, and B (2.0) has 2 sig figs. Therefore, the result P must be rounded to 2 significant figures.
Q4. The unit of density is kg/m³. This unit is classified as a derived unit because:
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Correct answer: B — It is derived from the multiplication of fundamental units.
Density is the ratio of mass to volume. Since mass (kg) and volume (m³) are fundamental units, density is a derived unit formed by combining them.
Q5. A vernier calliper has a least count of 0.01 cm. What does this value signify?
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Correct answer: C — The smallest measurement that the instrument can measure accurately.
The least count defines the smallest measurement that the instrument can measure accurately.
Q6. The ratio of the absolute error to the measured value is defined as:
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Correct answer: B — Relative error
The relative error is calculated as (Absolute Error / Measured Value).
Q7. The base SI unit for the amount of luminous intensity is:
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Correct answer: B — Candela
The SI base unit for luminous intensity (brightness) is the Candela (cd).
Q8. If two quantities A and B are measured and their sum S = A+B is calculated, the absolute error in S is generally found by:
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Correct answer: B — ΔA + ΔB
When adding quantities, the absolute errors add up: ΔS = ΔA + ΔB. (This is a fundamental rule for error propagation in simple addition).
Q9. Which of the following is a fundamental unit in the SI system for measuring time?
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Correct answer: C — Second
The SI unit for time is the second (s). The meter, kilogram, and ampere are also base units, but the question specifically asks for the unit of time.
Q10. What are the dimensions of acceleration?
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Correct answer: D — [LT⁻²]
Acceleration is defined as change in velocity over time. Velocity has dimensions [LT⁻¹]. Therefore, the dimensions of acceleration are [LT⁻²].
Q11. The dimensions of the physical quantity work (energy) are:
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Correct answer: A — M L² T⁻²
Work (Energy) is defined as Force times distance (W = Fd). Since Force (F=ma) has dimensions MLT⁻² and distance (L) has dimension L, the dimensions of work are (MLT⁻²) × L = ML²T⁻².
Q12. Which of the following is a base SI unit for the physical quantity electric current?
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Correct answer: D — Ampere
The base SI unit for electric current is the Ampere (A). Volt is the unit for potential difference, Ohm is the unit for resistance, and Watt is the unit for power (derived unit).
Q13. Which of the following statements is always true regarding the least count of a measuring instrument?
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Correct answer: A — The least count represents the smallest measurement that can be accurately recorded by the instrument.
The least count is the smallest measurement that can be measured or recorded by a particular measuring instrument. It defines the limit of precision for that instrument.
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