Concepts Of Physics MCQ Edition [Volume 1]PhysicsWave Motion and Waves on a String
A sonometer wire with a natural frequency of 240 Hz is made to vibrate using a tuning fork of frequency 480 Hz . The frequency at which the wire will vibrate is
Options
- A720 Hz
- Bwill not vibrate
- C480 Hz
- D240 Hz
Correct answer
C. 480 Hz
Step-by-step solution
When a sonometer wire is made to vibrate by an external source such as a tuning fork, it undergoes forced vibrations. In forced vibrations, the system oscillates with the frequency of the applied external periodic force, irrespective of its natural frequency. Since the frequency of the tuning fork is 480 Hz , the sonometer wire will vibrate with a frequency of 480 Hz . As 480 Hz is an integer multiple of the natural frequency ( 2 240 Hz ), the wire will vibrate in its second harmonic (resonance), but the frequency