List of top Physics Questions on Electromagnetic Spectrum asked in JEE Main

A monochromatic source of light operating at 15 kW emits \(2.5 \times 10^{22}\) photons/s. The region of an electromagnetic spectrum to which the emitted electromagnetic radiation belongs to ________.

Arrange the following in the ascending order of wavelength:
(A) Gamma rays (\( \lambda_1 \))
(B) X-ray (\( \lambda_2 \))
(C) Infrared waves (\( \lambda_3 \))
(D) Microwaves (\( \lambda_4 \))
Choose the most appropriate answer from the options given below:

The oscillating magnetic field in a plane electromagnetic wave is given by By = \(5 × 10^{–6}\) \(sin\;1000\;π(5x – 4 × 108\;t)T\). The amplitude of electric field will be:

Wavelengths assigned to gamma rays, infra-red rays, UV rays and microwaves are 1 , 2 , 3 & 4 respectively. Then :