MCQs on Electromagnetic Waves
Q: Electromagnetic waves are produced by
- A static charge
- An accelerated charge
- A moving charge
- Charged particles
Answer: (b) An accelerated charge
Q: In electromagnetic waves the phase difference between electric field vector and magnetic field vector is
Answer: (a) zero
Q: In an electromagnetic wave in free space, the root mean square value of the electric field is 6 V/m. The peak value of the magnetic field is
- 2.83 x 10-8 T
- 1.51 x 10-8 T
- 0.80 x 10-8 T
- 4 x 10-8 T
Answer: (a) 2.83 x 10-8 T
Q: Which of the following can be used to produce a propagating electromagnetic wave?
- Charge moving at a constant speed
- Chargeless particle
- Stationary charge
- An accelerating charge
Answer: (d) An accelerating charge
Q: To which part of the spectrum does EM waves belong if the energy of the wave is of the order of 15 KeV.
- X rays
- Infrared rays
- Ultraviolet rays
- Gamma rays
Answer: (a) X rays
Q: The ratio of the amplitude of the magnetic field to the amplitude of the electric field for electromagnetic wave propagation in a vacuum is equal to
- Speed of light in vacuum
- Reciprocal of the speed of light in vacuum
- The ratio of magnetic permeability to electrical susceptibility in a vacuum.
Answer: (c) Reciprocal of the speed of light in vacuum
Q: Which properties amount the following is false about electromagnetic waves?
- The energy in an electromagnetic wave is divided equally between electric and magnetic vectors.
- Both electric and magnetic field vectors are parallel to each other and perpendicular to the direction of propagation of the wave.
- These waves do not require any material medium for propagation
- Both electric and magnetic field vectors attain the maxima and minima at the same place and the same time
Answer: (b) Both electric and magnetic field vectors are parallel to each other and perpendicular to the direction of propagation of the wave.
Q: Which of the following rays are not electromagnetic waves?
- Gamma rays
- Beta rays
- Heat rays
- X rays
Answer: (b) Beta rays