All exercise Short Questions of Wave Motion of book Optics for BS/MSc Physics students.
Q.1 What are the types of waves? Give examples.
Answer: Mechanical waves are of two types.
- Electromagnetic Waves.
Examples of electromagnetic waves are radio waves, infrared waves, etc.
- Mechanical Waves
Mechanical waves are further divided into two types
- Transverse Waves, i.e. string waves .
- Longitudinal Waves, i.e. sound waves.
Q.2 Define phase velocity.
Answer: This is the speed at which the profile moves and is commonly known as the wave velocity or more specifically, as the phase velocity. The phase velocity carries a positive sign when the wave moves in the direction of increasing and a negative one in the direction of decreasing
.
Q.3 Differentiate between wave and pulse.
Answer: Disturbance produced in a medium cause the production of oscillations which propagate from one point to the other.
An instantaneous value of a wave is called pulse.
Q.4 How can you describe periodic and harmonic waves?
Answer: The simplest wave form where the profile is sine or cosine curve. These are variously known as sinusoidal waves, simple harmonic waves or more detailed form of harmonic motions.
A periodic wave is a wave with a repeating continuous pattern which determines its wavelength and frequency. It is characterized by the amplitude, a period and a frequency.
Q.5 State the principle of superposition.
Answer: The simplest additive property of wave is called superposition like interference, beats and stationary waves.
Q.6 What are the significance of plane wave?
Answer: It is the mathematical for moving wave in space along k direction. The plane wave is perhaps the simplest example of a three-dimensional wave. It exists at a given time, when all the surfaces upon which a disturbance has constant phase form a set of planes, each generally perpendicular to the propagation direction. There are quite practical reasons for studying this sort of disturbance, one of which is that by using optical devices we can readily produce light resembling plane wave.
