Two sources of sound placed close to each other are emitting progressive waves

⇦

⇨

Two sources of sound placed close to each other are emitting progressive waves given by y₁ = 4 sin 600 πt and y₂ = 5 sin 608 πt. An observer located near these two sources of sound will hear:

Options

(a) 4 beats per second with intensity ratio 25 : 16 between waxing and waning
(b) 8 beats per second with intensity ratio 25 : 16 between waxing and waning
(c) 8 beats per second with intensity ratio 81 : 1 between waxing and waning
(d) 4 beats per second with intensity ratio 81 : 1 between waxing and waning

Correct Answer:

4 beats per second with intensity ratio 81 : 1 between waxing and waning

Explanation:

2πf₁ = 600π , f₁ = 300 …(1)
2πf₂ = 608π , f₂ = 304 …(2)
| f₁ – f₂ | = 4 beats
Iₘₐₓ / Iₘ.ₙ = (A₁ + A₂)² / (A₁ – A₂)² = (5 + 4)² / (5 – 4)² = 81/1
where, A₁ , A₂ are amplitudes of given two sound wave.

Related Questions:

1. The de-Broglie wavelength of an electron having 80 eV of energy is nearly
2. Charge density for intrinsic semiconductor will be
3. The valence band and the conductance band of a solid overlap at low temperature
4. A simple pendulum is suspended from the ceiling of a lift. When the lift is at rest
5. The velocity of a particle performing simple harmonic motion, when it passes

Topics: Waves (80)
Subject: Physics (2479)

---

Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score

18000+ students are using NEETLab to improve their score. What about you?

Solve Previous Year MCQs, Mock Tests, Topicwise Practice Tests, Identify Weak Topics, Formula Flash cards and much more is available in NEETLab Android App to improve your NEET score.

---

Share this page with your friends