Electromagnetic Waves Test 01 Notes - Class 12

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CBSE TEST PAPER-01 
CLASS - XII PHYSICS (Electro magnetic waves) 
1.
What is the role of ozone in the atmosphere?
[1] 
2.
What is the nature of waves used in radar?
[1] 
3.
Write the application of Infra-red radiations?
[2] 
4.
Which constituent radiation of the electromagnetic spectrum is used?
(1) To photograph internal parts of human body.
(2) For air aircraft navigation
[2] 
5.
Electric field in a plane electromagnetic wave is given by
E Z = 60 sin 
( )
3
11
10 3
10 / .
2 2
x t
V m
? ?
+
? ?
? ?
 
(a) Write an expression for the magnetic field 
(b) What is the magnitude of wavelength and frequency of the wave? 
[2] 
6.
In a plane electromagnetic wave, the electric field oscillates sinusoid ally with a
frequency of 2 × 10
10
 Hz and amplitude 48V/m.
(a) What is the wavelength of the em. wave?
(b) Calculate the amplitude of the oscillating magnetic field.
(c) Calculate average energy density of the electromagnetic field of the wave?
[3] 
7.
Find the wavelength of electromagnetic waves of frequency 6 × 10
12
 Hg in free
space. Give two applications?
[3] 
8.
A plane monochromatic wave lies in the visible region. It is represented by the
sinusoidal variation with time by the following components of electric field
Ex = 0, Ey = 4 sin ( )
2
, x vt
p
?
? ?
- ? ?
? ?
Ez = 0 
Where ? = 5 × 10
14
 Hg  And ? is the wavelength of light.
(a) What is the direction of propagation of the wave? 
(b) What is its amplitude?  
(c) Compute the component of magnetic field? 
[3] 
9.
Write the characteristics of em waves? Write the expression for velocity of
electromagnetic waves in terms of permittivity and permeability of the
medium?
[3]