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Chapter 1: Waves — Online MCQ Test

PHYSICS · CLASS 12 INTERMEDIATE 2 YEAR · Telangana State Board
Practice Chapter 1: Waves with a free chapter-wise online MCQ test. This chapter covers: This chapter covers wave motion speed of transverse and longitudinal waves principle of superposition Doppler effect in sound wave interference and standing waves in pipes and stre.... AI-generated questions from basic to board-exam level, with instant results and explanations.

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Chapter 1: Waves — Important Questions & Answers

What is the speed of a transverse wave on a stretched string given by?
  • A. v = T/μ
  • B. v = √(T/μ)
  • C. v = √(μ/T)
  • D. v = Tμ
Answer: B. v = √(T/μ)
The wave speed on a stretched string depends on the tension T and mass per unit length μ as v = √(T/μ).
Which of the following is a longitudinal wave?
  • A. Light wave
  • B. Water surface wave
  • C. Sound wave in air
  • D. Wave on a stretched string
Answer: C. Sound wave in air
In sound waves, the particles of the medium vibrate parallel to the direction of wave propagation, so it is longitudinal.
A wave of frequency 200 Hz travels with speed 300 m/s. Its wavelength is:
  • A. 0.67 m
  • B. 1.5 m
  • C. 2 m
  • D. 60000 m
Answer: B. 1.5 m
Using v = fλ, we get λ = v/f = 300/200 = 1.5 m.
A sound source moving away from a stationary observer produces a frequency of 480 Hz. If the original frequency is 500 Hz, the observed change is due to:
  • A. increase in velocity of sound
  • B. increase in amplitude only
  • C. Doppler effect causing decrease in apparent frequency
  • D. reflection of sound from the source
Answer: C. Doppler effect causing decrease in apparent frequency
When the source moves away, the wavefronts get stretched and the observed frequency decreases, which is the Doppler effect.
A source of sound of frequency f moves with speed v_s toward a stationary observer. If the speed of sound is v, the apparent frequency is:
  • A. f(v - v_s)/v
  • B. f(v + v_s)/v
  • C. f v/(v - v_s)
  • D. f v/(v + v_s)
Answer: C. f v/(v - v_s)
For a moving source approaching a stationary observer, the Doppler formula is f' = f v/(v - v_s). The observed frequency increases.