JEE Questions for Physics Electromagnetic Waves Quiz 1 - MCQExams.com

Which of the following relations is correct ?

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  • 2)
    Physics-Electromagnetic Waves-69742.png

  • Physics-Electromagnetic Waves-69743.png

  • Physics-Electromagnetic Waves-69744.png
Which of the following shows greenhouse effect?
  • Ultraviolet rays
  • Infrared rays
  • X – rays
  • None of these
Solar radiation is
  • transverse electromagnetic waves
  • longitudinal electromagnetic waves
  • stationary waves
  • None of the above
What is order of energy of X-rays (EX ), radio waves (ER ) and microwaves (EM )?
  • EX < ER < EM
  • EX > EM > ER
  • EM > EX > ER
  • EM < ER < EX
During the propagation of electromagnetic waves in a medium,
  • electric energy density is double of the magnetic energy density
  • electric energy density is half of the magnetic energy density
  • electric energy density is equal to the magnetic energy density
  • Both electric and magnetic energy densities are zero
A plane electromagnetic wave of frequency 20 MHz travels through a space along x-direction. If the electric field vector at a certain point in space is 6 Vm-1, what is the magnetic field vector at that point?
  • 2 × 10-8 T
  • 2)
    Physics-Electromagnetic Waves-69691.png
  • 2 T

  • Physics-Electromagnetic Waves-69692.png
The speed of electromagnetic waves in vacuum depends upon the source of radiation. It
  • increases as we move from γ-rays to radio waves
  • decreases as we move from γ-rays to radio waves
  • is same for all of them
  • None of the above
An electromagnetic wave has
  • electric vector only
  • magnetic vector only
  • electric and magnetic vectors perpendicular to each other
  • Neither the electric vector nor the magnetic vector
A point source of electromagnetic radiation has an average power output of 1500 W. The maximum value of electric field at a distance of 3 m from this source in Vm -1 is
  • 500
  • 100
  • 500/3
  • 250/3
  • 10√5
The dielectric constant of air is 1.006. The speed of electromagnetic wave travelling in air is a × 108 ms-1, where, a is about
  • 3
  • 3.88
  • 2.5
  • 3.2
  • 2.8
An electromagnetic wave of frequency v = 3.0 MHz passes from vacuum into a dielectric medium with permittivity ε = 4.0. Then
  • wavelength is doubled and the frequency remains unchanged
  • wavelength is doubled and frequency becomes half
  • wavelength is halved and frequency remains unchanged
  • wavelength and frequency both remain unchanged
Electromagnetic waves can be deflected by
  • electric field only
  • magnetic field only
  • Both (and (2)
  • None of the above
In an electromagnetic wave, direction of propagation is in the direction of
  • E
  • B
  • E × B
  • None of these
Rank the following radiations according to their associated energies, greatest first.
I. Yellow light from a sodium lamp.
II. γ – rays emitted by a radioactive nucleus.
III. Radio waves emitted by the antenna.
IV. Microwaves beam emitted by radar.
  • II, I, IV, III
  • I, II, III, IV
  • III, IV, I, II
  • I, II, IV, III
Which of the following is absorbed by the ozone layer?
  • γ – rays
  • Visible light
  • Radio waves
  • Ultraviolet rays
An electromagnetic radiation has an energy of 13.2 keV. Then, the radiation belongs to the region of
  • visible light
  • ultraviolet
  • infrared
  • X – rays
The frequency 1057 MHz of radiation arising from two close energy levels in hydrogen belongs to
  • radio waves
  • infrared waves
  • microwaves
  • γ – rays
All components of the electromagnetic spectrum in vacuum have the same
  • velocity
  • energy
  • wavelength
  • frequency
The displacement current was first postulated by
  • Maxwell
  • Marconi
  • Ampere
  • Hertz
A plane electromagnetic wave is incident on a material surface. If the wave delivers momentum p and energy E, then
  • p = 0, E = 0
  • p ≠ 0, E ≠ 0
  • p ≠ 0, E = 0
  • p = 0, E ≠ 0
An expression for the magnetic field strength B at the point between the capacitor plates indicates in Fig. Express B in terms of the rate of change of the electric field strength i.e. dE/dt between the plates
Physics-Electromagnetic Waves-69701.png

  • Physics-Electromagnetic Waves-69702.png
  • 2)
    Physics-Electromagnetic Waves-69703.png
  • zero

  • Physics-Electromagnetic Waves-69704.png
Maxwell’s modified form of Ampere’s circuital law is

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  • 2)
    Physics-Electromagnetic Waves-69707.png

  • Physics-Electromagnetic Waves-69708.png

  • Physics-Electromagnetic Waves-69709.png

Physics-Electromagnetic Waves-69710.png
  • (i), (ii), (iii)
  • (i), (ii)
  • (i) and (iii) only
  • (i) and (iv) only
The equation out of four Maxwell’s equations which show electric field lines donot form closed loops are
  • (i) only
  • (i) and (iv) when E is independent of time.
  • (iv) only when E is independent of time
  • none of these.

Physics-Electromagnetic Waves-69712.png

  • Physics-Electromagnetic Waves-69713.png
  • 2)
    Physics-Electromagnetic Waves-69714.png

  • Physics-Electromagnetic Waves-69715.png
  • random
The wavelength of x-rays is of the order of
  • 1 metre
  • 1 cm
  • 1 micron
  • 1 angstrom
Which of the following is of shortest wavelength?
  • X-rays
  • γ-rays
  • microwaves
  • radiowaves
The voltage applied across an X-rays tube is nearly equal to
  • 10 V
  • 100 V
  • 1000 V
  • 10,000 V.
The minimum frequency vmin of continuous X-rays is related to the applied pot. diff. V as

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  • 2)
    Physics-Electromagnetic Waves-69718.png

  • Physics-Electromagnetic Waves-69719.png

  • Physics-Electromagnetic Waves-69720.png
In an electromagnetic wave, the average energy density associated with magnetic field is

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  • 2)
    Physics-Electromagnetic Waves-69723.png

  • Physics-Electromagnetic Waves-69724.png

  • Physics-Electromagnetic Waves-69725.png
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