Question

On which principle does the sonometer work?

• A. Hooke’s law
• B. Elasticity
• C. Resonance
• D. Newton’s law

Answer 1

The correct option is C

Resonance

The explanation for the correct option:

In the case of option C,

1. Sonometer is a device that works on the principle of resonance.
2. Resonance is a phenomenon of forced vibration in the sound wave.
3. Sonometer tends to vibrate at the resonant frequency with a larger amplitude.
4. At resonance the natural frequency of the sonometer becomes equal to the frequency of external force.
5. Sonometer is used to verify the laws of vibration of a stretched string.

The explanation for the incorrect options:

In the case of option A,

1. Hooke's law deals with the mechanical properties of solid as elasticity.
2. According to Hooke's law, within the elastic limit stress is directly proportional to the strain of a solid.

In the case of option B,

1. Elasticity is the mechanical property of a solid.
2. Elasticity is the inbuilt property of solids by which a solid can resist the deforming force and regain its original state.

In the case of option D,

1. Newton's law deals with laws of motion.

Hence, the correct option is C.