Wave motion; longitudinal and transverse waves; wave speed — NEET & JEE Questions

Question 1 · difficulty L1 · recall

In a transverse mechanical wave, how do particles of the medium oscillate relative to the direction of wave propagation?

• A. Parallel to the direction of propagation
• B. Perpendicular to the direction of propagation
• C. Only in the direction of gravity
• D. They do not oscillate

Question 2 · difficulty L2 · understanding

Which relation connects wave speed $v$, frequency $f$ and wavelength $\lambda$?

• A. $v=f\lambda$
• B. $v=f/\lambda$
• C. $v=\lambda/f$
• D. $v=f+\lambda$

Question 3 · difficulty L2 · understanding

A sound wave travels through air. What is transported over long distances by the wave?

• A. Air molecules themselves from the source to the listener
• B. Energy, while air particles oscillate about their mean positions
• C. Only mass and not energy
• D. Neither energy nor disturbance

Question 4 · difficulty L2 · understanding

In a longitudinal wave, a compression is a region where the medium has

• A. lower pressure and lower density
• B. higher pressure and higher density
• C. higher pressure and lower density
• D. zero particle displacement at all times

Question 5 · difficulty L3 · application

A wave has frequency $50\,\text{Hz}$ and wavelength $4.0\,\text{m}$. What is its speed?

• A. $12.5\,\text{m s}^{-1}$
• B. $46\,\text{m s}^{-1}$
• C. $200\,\text{m s}^{-1}$
• D. $400\,\text{m s}^{-1}$

Question 6 · difficulty L3 · application

A wave travels at $300\,\text{m s}^{-1}$ and has frequency $150\,\text{Hz}$. What is its wavelength?

• A. $0.50\,\text{m}$
• B. $2.0\,\text{m}$
• C. $45\,\text{m}$
• D. $450\,\text{m}$

Question 7 · difficulty L3 · application

A source produces waves of frequency 20 Hz in a medium where the wave speed is 100 m/s. If the source frequency is doubled while the medium is unchanged, what is the new wavelength?

• A. 10 m
• B. 5 m
• C. 2.5 m
• D. 1.25 m

Question 8 · difficulty L3 · application

A pulse takes $0.20\,\text{s}$ to travel $30\,\text{m}$ along a stretched string. What is the wave speed on the string?

• A. $6\,\text{m s}^{-1}$
• B. $60\,\text{m s}^{-1}$
• C. $150\,\text{m s}^{-1}$
• D. $600\,\text{m s}^{-1}$

Question 9 · difficulty L4 · application

A string under tension supports a wave of speed $v$. If the tension is made four times as large while the linear mass density remains unchanged, what is the new wave speed?

• A. $v/4$
• B. $v/2$
• C. $2v$
• D. $4v$

Question 10 · difficulty L4 · application

A sinusoidal wave of frequency 25 Hz travels on a string at 100 m/s. The tension is then increased by a factor of 4 while the source frequency remains unchanged. What is the new wavelength?

• A. 2 m
• B. 4 m
• C. 8 m
• D. 16 m