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Nature & Propagation of Sound — Homi Bhabha Exam Physics MCQs with Solutions
Free Homi Bhabha Exam Physics Nature & Propagation of Sound MCQs with step-by-step solutions (6 questions). Part of Sound. Practise online on Prepizo — no login needed.
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Questions with solutions
Q1 — Nature & Propagation of Sound · medium · theory
Sound waves are:
A. electromagnetic waves
B. longitudinal mechanical waves that need a material medium ✓ Correct
C. transverse waves that travel through vacuum
D. waves that need no medium
Solution: Sound is a longitudinal mechanical wave; it needs particles of a medium (solid, liquid or gas) to travel.
Q2 — Nature & Propagation of Sound · hard · theory
An electric bell ringing inside a sealed glass jar becomes inaudible as air is pumped out. This shows that sound:
A. is an electromagnetic wave
B. needs light to travel
C. cannot travel through vacuum ✓ Correct
D. travels faster in vacuum
Solution: With no air (medium) there are no particles to carry the compressions and rarefactions, so sound cannot propagate.
Q3 — Nature & Propagation of Sound · hard · theory
Sound travels fastest in:
A. solids ✓ Correct
B. liquids
C. vacuum
D. gases
Solution: Particles are most tightly packed in solids, so sound travels fastest in solids and slowest in gases (and not at all in vacuum).
Q4 — Nature & Propagation of Sound · medium · numerical
Sound travels 1500 m in water in 1 s. The speed of sound in water is:
A. 150 m/s
B. 750 m/s
C. 15000 m/s
D. 1500 m/s ✓ Correct
Solution: Speed $= \dfrac{\text{distance}}{\text{time}} = \dfrac{1500}{1} = 1500$ m/s.
Q5 — Nature & Propagation of Sound · medium · theory
The regions of high pressure/density in a sound wave travelling through air are called:
A. crests
B. compressions ✓ Correct
C. rarefactions
D. troughs
Solution: In a longitudinal sound wave, compressions are high-density regions and rarefactions are low-density regions.
Q6 — Nature & Propagation of Sound · hard · numerical
Sound takes 3 s to travel from a source to a listener 1020 m away. The speed of sound in that air is:
A. 3060 m/s
B. 306 m/s
C. 1020 m/s
D. 340 m/s ✓ Correct
Solution: Speed $= \dfrac{1020}{3} = 340$ m/s.