Waves

Free sample questions

Waves — sample Physics questions with answers

1. Question 1

   Which of the following waves is a longitudinal wave?

   • ASound waves
   • BRadio waves
   • CWater waves
   • DLight waves

   Answer: A. Sound waves

   Longitudinal waves are waves in which the particles of the medium vibrate parallel to the direction of wave propagation. Sound waves are the only example of longitudinal waves here, while water, radio, and light waves are transverse waves.

2. Question 2

   A water wave has a wavelength $\lambda =0.4\text{ m}$ and travels with speed $v=2.0{\text{ m s}}^{-1}$. What is the frequency of the wave?

   • A$0.2\text{ Hz}$
   • B$0.8\text{ Hz}$
   • C$5.0\text{ Hz}$
   • D$8.0\text{ Hz}$

   Answer: C. $5.0\text{ Hz}$

   Using the wave speed formula $v=f\lambda$, the frequency is calculated as $f=\frac{v}{\lambda }=\frac{2.0{\text{ m s}}^{-1}}{0.4\text{ m}}=5.0\text{ Hz}$.

3. Question 3

   In the Barton's pendulum experiment, when the driving pendulum is swung, it is found that other pendulums with the same string length begin to oscillate with maximum amplitude. What physical phenomenon causes this to happen?

   • ADamping
   • BReflection
   • CRefraction
   • DResonance

   Answer: D. Resonance

   Resonance occurs when a system is forced to vibrate at a natural frequency equal to the driving system's frequency, causing the system to vibrate with maximum amplitude.

4. Question 4

   A vibrator produces water waves on the water surface. When the amplitude of the vibrator's oscillation is increased, what is the effect on the wave?

   • AThe wave frequency increases
   • BThe wave propagation speed increases
   • CThe wavelength decreases
   • DThe wave energy increases

   Answer: D. The wave energy increases

   Amplitude is directly proportional to the energy carried by the wave. Increasing the amplitude does not change the frequency, speed, or wavelength in the same medium.

5. Question 5

   Water waves travel at an angle of incidence $40^{\circ }$ to the normal before being reflected by a straight reflector. What is the angle of reflection of the waves?

   • A$40^{\circ }$
   • B$50^{\circ }$
   • C$130^{\circ }$
   • D$20^{\circ }$

   Answer: A. $40^{\circ}$

   According to the law of reflection, the angle of incidence is equal to the angle of reflection, i.e. $40^{\circ }$.