Practice MCQ Questions and answers on Physics-GK

The waves produced on the surface of water in the pond is an example of transverse waves as particles of the medium do not move along with the wave. Only the disturbance is carried forward. Another example of such waves is the vibrations of a string.

When a light wave is reflected from an object, it changes not only its amplitude but also its phase according to the properties of the object at a particular point. The velocity and momentum are just reversed in another direction.

A doppler effect occurs when a source of sound moves away from you or towards you.

Stationary wave is formed by two waves of same frequency travelling in the opposite direction.

Ultrasound devices operate with minimum frequency from 20kHz.

Light and Radio waves are both different frequency/wavelengths of electromagnetic radiation, which consists of two components electric and magnetic of perpendicular, transverse waves.
Sound, on the other hand, is a longitudinal wave which oscillates parallel to it's medium (back and forth instead of up and down).

Rectifier is the name of the device used to convert alternating current into direct current.

A Step-Up transformer increases voltage.

A transformer is used to decrease or increase AC voltage.

An AC meter calibrated to accurately read RMS voltage or current on a pure sine wave will not give the proper value while indicating the magnitude of anything other than a perfect sine wave. This includes triangle waves, square waves, or any kind of distorted sine wave.