An echo returned in 0.5 s. If speed of sound is 340 m/s, the distance of reflecting surface is MCQ with Answer and Explanation

Question

Share Report Error

An echo returned in 0.5 s. If speed of sound is 340 m/s, the distance of reflecting surface is

A. 680 m

B. 340 m

C. 85 m

D. 170 m

Answer: Option C

Solution (By JKSSB Mock Tests)

d = (v×t)/2 = (340×0.5)/2 = 170/2 = 85 m. Minimum distance for echo perception is about 17 m. Remember divide by 2 for one-way distance.

This question belongs to: Science Physics

Request complete Subject PDF

Discuss this Question (0)

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

Practice More Physics Questions

Question #1

The dimensional formula of surface tension is

A. [MT⁻²]

B. [MLT⁻²]

C. [ML⁰T⁻²]

D. [ML⁻¹T⁻²]

View Answer & Solution Discuss

Get Complete Subject PDF for Science

Correct Answer: Option A

Explanation:
Surface tension = force/length. Force dimensions [MLT⁻²], length [L], so [MLT⁻²]/[L] = [MT⁻²]. Also energy per area gives same dimensions: [ML²T⁻²]/[L²] = [MT⁻²].

This question belongs to: Science Physics

Question #2

Three 3Ω resistors in parallel: equivalent resistance is:

A. 9Ω

B. 1Ω

C. 3Ω

D. 0.33Ω

View Answer & Solution Discuss

Get Complete Subject PDF for Science

Correct Answer: Option B

Explanation:
1/R_eq = 1/3 + 1/3 + 1/3 = 1 ⇒ R_eq = 1Ω. For n equal resistors in parallel: R_eq = R/n. Memory tip: 'Parallel: reciprocal sum; result < smallest resistor'. Basic circuit calculation frequently tested in competitive exams to verify parallel combination formula.

This question belongs to: Science Physics

Question #3

The instrument that measures the density of a liquid is

A. Hydrometer

B. Lactometer

C. Hygrometer

D. Barometer

View Answer & Solution Discuss

Get Complete Subject PDF for Science

Correct Answer: Option A

Explanation:
Hydrometer measures relative density. Lactometer for milk, but general is hydrometer.

This question belongs to: Science Physics

Explore All Physics MCQs