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. A series combination of n₁ capacitors, each of value C₁, is charged by a source
2. Cathode rays are produced when the pressure is of the order of
3. A 1m long wire of diameter 0.31 mm has a resistance of 4.2Ω. If it is replaced by
4. The volume of a nucleus is directly proportional to
5. Two identical cells of the same e.m.f. and same internal resistance

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