The least count of a screw gauge is 0.001 cm. The reading of a measurement is 0.250 cm. How many significant figures does it have? MCQ with Answer and Explanation

The least count of a screw gauge is 0.001 cm. The reading of a measurement is 0.250 cm. How many significant figures does it have?
A. 3
B. 1
C. 4
D. 2
Answer: Option A
Solution (By JKExamLibrary)
Reading 0.250 cm has three significant figures (2,5, and trailing zero after decimal). Least count gives precision, trailing zero indicates measurement to 0.001 cm, so it's significant.

This question belongs to: Science Physics

Discuss this Question (0)

No comments yet. Be the first to start the discussion!

Practice More Physics Questions

Question #1 Report Error
A piece of ice of density 0.9 g/cm³ floats in water. Fraction of volume above water is
A. 0.2
B. 0.1
C. 0.9
D. 0.5

Correct Answer: Option B


Explanation:
Submerged fraction = ρ_ice/ρ_water = 0.9, above = 0.1 (10%).

This question belongs to: Science Physics
Question #2 Report Error
Which of the following physical quantities has the same dimensional formula as that of pressure?
A. Momentum per unit area
B. Force per unit length
C. Energy per unit volume
D. Power per unit volume

Correct Answer: Option C


Explanation:
Pressure has dimensions [ML⁻¹T⁻²]. Energy per unit volume: Energy is [ML²T⁻²], volume is [L³], so [ML²T⁻²]/[L³] = [ML⁻¹T⁻²], matching pressure. Force per unit length is [MLT⁻²]/[L] = [MT⁻²]. Momentum per unit area is [MLT⁻¹]/[L²] = [ML⁻¹T⁻¹]. Power per unit volume is [ML²T⁻³]/[L³] = [ML⁻¹T⁻³]. This dimensional equivalence explains why pressure appears in Bernoulli's equation alongside energy density. Memory aid: Pressure and energy density both represent stored energy per spatial dimension.

This question belongs to: Science Physics
Question #3 Report Error
Which of the following is not a source of renewable energy?
A. Sun
B. Natural gas
C. Tides
D. Wind

Correct Answer: Option B


Explanation:
Natural gas is fossil fuel, non-renewable.

This question belongs to: Science Physics