Electromagnetic Waves Practice Questions - DPP for JEE

 Page 1


PART-I (Single Correct MCQs)
1. An electromagnetic wave in vacuum has the electric and magnetic field 
 and , which are always perpendicular to each other. The direction
of polarization is given by  and that of wave propagation by . Then
(a) and 
(b) and 
(c) and 
(d) and 
2. If E and B represent elctric and magnetic field vectors of the
electromagnetic wave, the direction of propagation of electromagnetic
wave is along
(a) (b) 
(c) (d) 
3. The figure here gives the electric field of an electromagnetic wave at a
Page 2


PART-I (Single Correct MCQs)
1. An electromagnetic wave in vacuum has the electric and magnetic field 
 and , which are always perpendicular to each other. The direction
of polarization is given by  and that of wave propagation by . Then
(a) and 
(b) and 
(c) and 
(d) and 
2. If E and B represent elctric and magnetic field vectors of the
electromagnetic wave, the direction of propagation of electromagnetic
wave is along
(a) (b) 
(c) (d) 
3. The figure here gives the electric field of an electromagnetic wave at a
certain point and a certain instant. The wave is transporting energy in
the negative z-direction. The direction of the magnetic field of the wave
at that point and instant is
(a) + ve x-direction
(b) –ve x-direction
(c) +ve z-direction
(d) –ve y-direction
4. A plane electromagnetic wave is incident on a material surface. If the
wave delivers momentum p and energy E, then
(a) p = 0, E = 0
(b)
(c)
(d)
5. The electric field of an electromagnetic wave travelling through vaccum is
given by the equation E = E
0
 sin (kx – ?t). The quantity that is
independent of wavelength is
(a) k? (b) (c) k
2
? (d) ?
6. The figure shows graphs of the electric field
magnitude E versus time t for four uniform electric
fields, all contained within identical circular regions.
Which of them is according to the magnitudes of the
magnetic field?
(a) A
(b) B
Page 3


PART-I (Single Correct MCQs)
1. An electromagnetic wave in vacuum has the electric and magnetic field 
 and , which are always perpendicular to each other. The direction
of polarization is given by  and that of wave propagation by . Then
(a) and 
(b) and 
(c) and 
(d) and 
2. If E and B represent elctric and magnetic field vectors of the
electromagnetic wave, the direction of propagation of electromagnetic
wave is along
(a) (b) 
(c) (d) 
3. The figure here gives the electric field of an electromagnetic wave at a
certain point and a certain instant. The wave is transporting energy in
the negative z-direction. The direction of the magnetic field of the wave
at that point and instant is
(a) + ve x-direction
(b) –ve x-direction
(c) +ve z-direction
(d) –ve y-direction
4. A plane electromagnetic wave is incident on a material surface. If the
wave delivers momentum p and energy E, then
(a) p = 0, E = 0
(b)
(c)
(d)
5. The electric field of an electromagnetic wave travelling through vaccum is
given by the equation E = E
0
 sin (kx – ?t). The quantity that is
independent of wavelength is
(a) k? (b) (c) k
2
? (d) ?
6. The figure shows graphs of the electric field
magnitude E versus time t for four uniform electric
fields, all contained within identical circular regions.
Which of them is according to the magnitudes of the
magnetic field?
(a) A
(b) B
(c) C
(d) D
7. The electric field part of an electromagnetic wave in a medium is
represented by E
x
=0;
;
E
z 
= 0. The wave is :
(a) moving along x direction with frequency 10
6
 Hz and wave length 100 m.
(b) moving along  x direction with frequency 10
6
 Hz and wave length 200
m.
(c) moving along – x direction with frequency 10
6
 Hz and wave length 200
m.
(d) moving along y direction with frequency 2p × 10
6
 Hz and wave length
200 m.
8. The speed of electromagnetic wave in vacuum depends upon the source
of radiation. It
(a) increases as we move from ?-rays to radio waves
(b) decreases as we move from ?-rays to radio waves
(c) is same for all of them
(d) None of these
9. The energy of electromagnetic wave in vacuum is given by the relation
(a)
(b)
(c)
(d)
10. If microwaves, X rays, infrared, gamma rays, ultra-violet, radio waves
and visible parts of the electromagnetic spectrum are denoted by M, X,
Page 4


PART-I (Single Correct MCQs)
1. An electromagnetic wave in vacuum has the electric and magnetic field 
 and , which are always perpendicular to each other. The direction
of polarization is given by  and that of wave propagation by . Then
(a) and 
(b) and 
(c) and 
(d) and 
2. If E and B represent elctric and magnetic field vectors of the
electromagnetic wave, the direction of propagation of electromagnetic
wave is along
(a) (b) 
(c) (d) 
3. The figure here gives the electric field of an electromagnetic wave at a
certain point and a certain instant. The wave is transporting energy in
the negative z-direction. The direction of the magnetic field of the wave
at that point and instant is
(a) + ve x-direction
(b) –ve x-direction
(c) +ve z-direction
(d) –ve y-direction
4. A plane electromagnetic wave is incident on a material surface. If the
wave delivers momentum p and energy E, then
(a) p = 0, E = 0
(b)
(c)
(d)
5. The electric field of an electromagnetic wave travelling through vaccum is
given by the equation E = E
0
 sin (kx – ?t). The quantity that is
independent of wavelength is
(a) k? (b) (c) k
2
? (d) ?
6. The figure shows graphs of the electric field
magnitude E versus time t for four uniform electric
fields, all contained within identical circular regions.
Which of them is according to the magnitudes of the
magnetic field?
(a) A
(b) B
(c) C
(d) D
7. The electric field part of an electromagnetic wave in a medium is
represented by E
x
=0;
;
E
z 
= 0. The wave is :
(a) moving along x direction with frequency 10
6
 Hz and wave length 100 m.
(b) moving along  x direction with frequency 10
6
 Hz and wave length 200
m.
(c) moving along – x direction with frequency 10
6
 Hz and wave length 200
m.
(d) moving along y direction with frequency 2p × 10
6
 Hz and wave length
200 m.
8. The speed of electromagnetic wave in vacuum depends upon the source
of radiation. It
(a) increases as we move from ?-rays to radio waves
(b) decreases as we move from ?-rays to radio waves
(c) is same for all of them
(d) None of these
9. The energy of electromagnetic wave in vacuum is given by the relation
(a)
(b)
(c)
(d)
10. If microwaves, X rays, infrared, gamma rays, ultra-violet, radio waves
and visible parts of the electromagnetic spectrum are denoted by M, X,
I, G, U, R and V then which of the following is the arrangement in
ascending order of wavelength ?
(a) R, M, I, V, U, X and G
(b) M, R, V, X, U, G and I
(c) G, X, U, V, I, M and R
(d) I, M, R, U, V, X and G
11. Out of the following options which one can be used to produce a
propagating electromagnetic wave ?
(a) A charge moving at constant velocity
(b) A stationary charge
(c) A chargeless particle
(d) An accelerating charge
12. The pressure exerted by an electromagnetic wave of intensity I
(watts/m
2
) on  a non reflecting surface is [c is the velocity of light]
(a) Ic
(b) Ic
2
(c) I/c
(d) I/c
2
13. Which of the following electromagnetic waves has minimum frequency
?
(a) Microwaves
(b) Audible waves
(c) Ultrasonic wave
(d) Radiowaves
14. All components of the electromagnetic spectrum in vacuum have the
same
(a) energy
(b) velocity
(c) wavelength
Page 5


PART-I (Single Correct MCQs)
1. An electromagnetic wave in vacuum has the electric and magnetic field 
 and , which are always perpendicular to each other. The direction
of polarization is given by  and that of wave propagation by . Then
(a) and 
(b) and 
(c) and 
(d) and 
2. If E and B represent elctric and magnetic field vectors of the
electromagnetic wave, the direction of propagation of electromagnetic
wave is along
(a) (b) 
(c) (d) 
3. The figure here gives the electric field of an electromagnetic wave at a
certain point and a certain instant. The wave is transporting energy in
the negative z-direction. The direction of the magnetic field of the wave
at that point and instant is
(a) + ve x-direction
(b) –ve x-direction
(c) +ve z-direction
(d) –ve y-direction
4. A plane electromagnetic wave is incident on a material surface. If the
wave delivers momentum p and energy E, then
(a) p = 0, E = 0
(b)
(c)
(d)
5. The electric field of an electromagnetic wave travelling through vaccum is
given by the equation E = E
0
 sin (kx – ?t). The quantity that is
independent of wavelength is
(a) k? (b) (c) k
2
? (d) ?
6. The figure shows graphs of the electric field
magnitude E versus time t for four uniform electric
fields, all contained within identical circular regions.
Which of them is according to the magnitudes of the
magnetic field?
(a) A
(b) B
(c) C
(d) D
7. The electric field part of an electromagnetic wave in a medium is
represented by E
x
=0;
;
E
z 
= 0. The wave is :
(a) moving along x direction with frequency 10
6
 Hz and wave length 100 m.
(b) moving along  x direction with frequency 10
6
 Hz and wave length 200
m.
(c) moving along – x direction with frequency 10
6
 Hz and wave length 200
m.
(d) moving along y direction with frequency 2p × 10
6
 Hz and wave length
200 m.
8. The speed of electromagnetic wave in vacuum depends upon the source
of radiation. It
(a) increases as we move from ?-rays to radio waves
(b) decreases as we move from ?-rays to radio waves
(c) is same for all of them
(d) None of these
9. The energy of electromagnetic wave in vacuum is given by the relation
(a)
(b)
(c)
(d)
10. If microwaves, X rays, infrared, gamma rays, ultra-violet, radio waves
and visible parts of the electromagnetic spectrum are denoted by M, X,
I, G, U, R and V then which of the following is the arrangement in
ascending order of wavelength ?
(a) R, M, I, V, U, X and G
(b) M, R, V, X, U, G and I
(c) G, X, U, V, I, M and R
(d) I, M, R, U, V, X and G
11. Out of the following options which one can be used to produce a
propagating electromagnetic wave ?
(a) A charge moving at constant velocity
(b) A stationary charge
(c) A chargeless particle
(d) An accelerating charge
12. The pressure exerted by an electromagnetic wave of intensity I
(watts/m
2
) on  a non reflecting surface is [c is the velocity of light]
(a) Ic
(b) Ic
2
(c) I/c
(d) I/c
2
13. Which of the following electromagnetic waves has minimum frequency
?
(a) Microwaves
(b) Audible waves
(c) Ultrasonic wave
(d) Radiowaves
14. All components of the electromagnetic spectrum in vacuum have the
same
(a) energy
(b) velocity
(c) wavelength
(d) frequency
15. Which of the following statement is false for the properties of
electromagnetic waves?
(a) Both electric and magnetic field vectors attain the maxima and minima
at the same place and same time.
(b) The energy in electromagnetic wave is divided equally between electric
and magnetic vectors
(c) Both electric and magnetic field vectors are parallel to each other and
perpendicular to the direction of propagation of wave
(d) These waves do not require any material medium for propagation.
16. A radiation of energy ‘E’ falls normally on a perfectly reflecting
surface. The momentum transferred to the surface is (c = Velocity of
light)
(a)
(b)
(c)
(d)
17. If v
s
, v
x
 and v
m
 are the speed of soft gamma rays, X-rays and
microwaves respectively in vacuum, then
(a) v
s
 > v
x
 > v
m
(b) v
s
 < v
x
 < v
m
(c) v
s
 > v
x
 < v
m
(d) v
s
 = v
x
 = v
m
18. An electromagnetic wave going through vacuum is described by E =
E
0
sin(kx – ?t); B = B
0
 sin (kx – ?t). Which of the following equations