MCQ on Electromagnetic Wave with Answers

Electromagnetic waves are created when electric and magnetic fields interact and fluctuate over time) These waves would almost probably reach beyond space, as they are tied to electricity and magnetism.
Maxwell’s equations are used to derive the electromagnetic equations. According to Maxwell, these EM waves have a wide range of unique qualities that can be used for a variety of reasons. The coupled temporally changing electric and magnetic fields that travel through space are known as electromagnetic waves.
The magnetic field changes over time and gives rise to the electric field, which then changes over time and gives rise to the magnetic field and so on. Electromagnetic waves are created when time-varying electric and magnetic fields are linked and propagate together in space)

1. Which of the following waves is used in modern EDM?

a) Visible rays
b) Thermal IR
c) Modulated IR
d) Radio waves

Answer: Correct option will be: (c) Modulated IR

Reason: These waves are used in modern EDMs because they can receive the reflected waves from a distance of around 100 km.

3. Which characteristic of an electromagnetic wave is affected by the medium through which it travels?

a) Time period
b) Velocity
c) Wavelength
d) Frequency

Answer: Correct option will be: (b) velocity

Reason: The frequency, wavelength, and time period of a wave can all change depending on the source of the wave) The velocity of an electromagnetic wave, on the other hand, is determined by the medium through which it travels. The speed of light is the velocity of a wave in a vacuum, which is considered to be 3×108m/s.

3. How do EDMs measure distance?

a) Frequency
b) Wave length
c) Phase difference
d) Amplitude

Answer: Correct option will be: (c) Phase difference)

4. Which of the waves is used by the tellurometer, a type of EDM?

a) Microwaves
b) Infrared waves
c) Radio waves
d) Visible rays

Answer: Correct option will be: (c) Radio waves

Reason: Tellurometers typically have a range of 100 kilometers, meaning they can measure distances up to 100 kilometers. It requires a high-range propagating wave that can reflect back to the instrument in order to perform effectively.

5. Which of the given formats is used to represent electromagnetic waves?

a) Longitudinal waves
b) Transverse waves
c) Sinusoidal waves
d) Surface waves

Answer: Correct option will be: (c) Sinusoidal waves.

6. State true or false) High frequency propagation is utilized to improve accuracy.

a) True
b) False

Answer: Correct option will be: (a) true

Reason: It is suggested to use an exceptionally high propagation frequency to maximize accuracy. However, phase comparison techniques that are now available cannot be applied at frequencies higher than 5Ghz, which relates to a wavelength of 0.6 m.

7. Which of the given formats can be used to express phase difference?

a) Meter per second
b) Meter
c) Cycles
d) Seconds

Answer: Correct option will be: (c) Cycles.

Reason: The phase difference between sent and reflected signals can be used to measure the distance between two-point scans in a total station. The fraction of cycles can be used to indicate phase difference, which offers the best output for simple calculation and understanding.

8. Which of the following is the correct sequence for EDM propagation’s foundation?

a) Propagation, generation, reflection and reception
b) Generation, reception, reflection and propagation
c) Generation, propagation, reception and reflection
d) Generation, propagation, reflection and reception

Answer: Correct option will be: (d) Generation, propagation, reflection and reception.

Reason: The creation, propagation, reflection, and later reception of electromagnetic waves are used in the electronic distance measurement method. The type of electromagnetic waves produced is determined by a number of elements, the most important of which is the nature of the electrical signal used to generate the waves. It continues in the above-mentioned order with no interruptions.

9. Electromagnetic waves are generated by

a) Stationary charge
b) Accelerated charge
c) Charge in motion
d) Electrically charged particles

Answer: Correct option will be: (b) Accelerated charge)

10. Which of the following statements regarding electromagnetic waves is false?

a) In an electromagnetic wave, the energy is split evenly between the electric and magnetic vectors.
b) The vectors of the electric and magnetic fields are perpendicular to the wave’s propagation direction and parallel to each other.
c) The propagation of these waves is not dependent on any physical medium.
d) The peaks and minima of both the electric and magnetic field vectors occur at the same location and time)

Answer: Correct option will be: (b) The vectors of the electric and magnetic fields are perpendicular to the wave’s propagation direction and parallel to each other.

11. Which of the mentioned waves are responsible for telecommunication?

a) UV rays
b) IR
c) Microwaves
d) Visible light

Answer: Correct option will be: (c) Microwaves

12. The root mean square value of the electric field in a free space electromagnetic wave is 6 V/m. The magnetic field’s maximum value is

a) 2.83×10-8 T
b) 1.51×10-8 T
c) 0.80×10-8 T
d) 4×10-8 T

Answer: Correct option will be: (a)2.83×10-8 T.

13. If the energy of an EM wave is on the order of 15 keV, which section of the spectrum does it belong to?
a) X- rays
b) Infrared rays
c) Ultraviolet rays
d) Gamma rays

Answer: Correct option will be: (a) X- rays.

14. For electromagnetic wave propagation in a vacuum, the ratio of the amplitude of the magnetic field to the amplitude of the electric field is equal to