Simple harmonic motion and waves

Class 10 · Physics · 6 questions

Name: ____________________ Date: ____________

A pendulum completes 20 vibrations in 10 s. What is its frequency?
- A 10 Hz
- B 2 Hz
- C 200 Hz
- D 0.5 Hz
The time period T and frequency f are related by:
- A T = 2 f
- B T = 1 / f
- C T = f2
- D T = f
A wave has frequency 50 Hz and wavelength 4 m. What is its speed?
- A 12.5 m/s
- B 200 m/s
- C 46 m/s
- D 54 m/s
Sound waves are:
- A Transverse waves
- B Not waves
- C Electromagnetic waves
- D Longitudinal waves
In a transverse wave, the particles of the medium vibrate:
- A At right angles to the direction of the wave
- B They do not move
- C In circles only
- D Along the direction of the wave
The period of a simple pendulum depends on its:
- A Material
- B Mass
- C Colour
- D Length

Answer key

1. B, 2. B, 3. B, 4. D, 5. A, 6. D

Frequency = number of vibrations / time = 20 / 10 = 2 Hz.
Period is the reciprocal of frequency.
v = f x wavelength = 50 x 4 = 200 m/s.
Particles of the medium vibrate along the direction of travel, so sound is longitudinal.
In a transverse wave the vibration is perpendicular to the direction of travel.
T = 2 pi times the square root of (L / g), so it depends on length and g, not mass.