A radar transmitter generates waves of frequency 3 × 10 9 Hz . What is the wavelength ?

We know that, c = λ ν , here c is speed of light. ⇒ λ = c / ν = 3 × 10 8 3 × 10 9 = 0 . 1 m λ = 0 . 1 m = 10 cm

A plane electromagnetic wave has a maximum electric field of 3 . 20 × 10 - 4 Vm - 1 . What is maximum magnetic field?

B 0 · C = E 0 B 0 = E 0 / c = 3 . 2 × 10 - 4 3 × 10 8 = 1 . 07 × 10 - 12 T B 0 = 1 . 07 × 10 - 12 T

In a plane EM wave, the magnetic field oscillates sinusoidally with a frequency of 2 . 0 × 10 10 Hz and an amplitude of 46 Wb m - 2 . Find the wavelength of the wave and the amplitude of the oscillating electric field.

(i) E → & B → have same frequency, wavelength and speed in plane. So, ν is same for both So, λ = c / ν = 3 × 10 8 2 × 10 10 = 1 . 5 × 10 - 2 m Wavelength of E → = 1 . 5 × 10 - 12 m (ii) B 0 C = E 0 E 0 = 46 × 3 × 10 8 = 138 × 10 8 v / m Amplitude of electric E 0 = 1 . 38 × 10 10 v / m .

E M B I B E

NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 13 - Electromagnetic Waves>QUESTIONS>Q 2

MEDIUM

12th ICSE

IMPORTANT

Earn 100

Describe, with the help of a diagram, the electromagnetic spectrum from gamma rays to radio waves, showing approximate wavelength ranges.

Important Questions on Electromagnetic Waves

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12th ICSE

IMPORTANT

NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 13 - Electromagnetic Waves>QUESTIONS>Q 3

Describe very briefly any four regions of electromagnetic spectrum, mentioning their special properties/features.

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IMPORTANT

NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 13 - Electromagnetic Waves>QUESTIONS>Q 4

Electromagnetic spectrum is commonly classified as gamma rays, X-rays, UV-rays, visible light, IR-rays, etc. Mention very briefly two special features of any three of these, with respect to their production (source) and properties.

MEDIUM

12th ICSE

IMPORTANT

NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 13 - Electromagnetic Waves>QUESTIONS>Q 1

Electromagnetic waves enter a medium of relative permeability