NEET Waves — Set 13

Question 1

A longitudinal wave in a medium has a speed of 1500 m/s and a density of 1200 kg/m³. What is the bulk modulus of the medium?

Accepted Answer

Speed: $ v = \sqrt{\frac{B}{\rho}} $. $ 1500 = \sqrt{\frac{B}{1200}} \Rightarrow 1500^2 = \frac{B}{1200} $. $ B = 1500^2 \times 1200 = 2.7 \times 10^9 \, \text{Pa} $.

Question 2

What is the physical basis for the formation of beats in sound waves?

Accepted Answer

Beats arise from the superposition of two waves with slightly different frequencies, causing periodic constructive and destructive interference, perceived as amplitude variation.

Question 3

A pipe closed at one end has a length of 0.25 m and resonates at its fundamental frequency with a speed of sound of 340 m/s. What is the frequency?

Accepted Answer

Fundamental: $ v_1 = \frac{v}{4L} $. $ v_1 = \frac{340}{4 \times 0.25} = \frac{340}{1} = 340 \, \text{Hz} $.

NEET Physics: Waves — Practice Set 13

Q1. A longitudinal wave in a medium has a speed of 1500 m/s and a density of 1200 kg/m³. What is the bulk modulus of the medium?

Q2. What is the physical basis for the formation of beats in sound waves?

Q3. A pipe closed at one end has a length of 0.25 m and resonates at its fundamental frequency with a speed of sound of 340 m/s. What is the frequency?

Q4. What is the significance of the beat frequency when two sound waves interfere?

Q5. A longitudinal wave in a medium has a speed of 1700 m/s and a bulk modulus of 2.89 × 10⁹ Pa. What is the density of the medium?

Q6. A longitudinal wave in a medium has a speed of 1550 m/s and a density of 1200 kg/m³. What is the bulk modulus of the medium?

Q7. What is the key difference between a progressive wave and a standing wave?

Q8. What type of wave is produced when a stone is dropped into a still pond?

Q9. A pipe open at both ends has a length of 0.51 m and a speed of sound of 340 m/s. What is the frequency of its third harmonic?

Q10. A wave is described by \( y(x, t) = 0.06 \sin (30x - 90t) \), where \( x \) and \( y \) are in meters and \( t \) in seconds. What is the wave speed?