# MCQs On Electromagnetic Waves for NEET pdf

Here we prepared a comprehensive Electromagnetic Waves MCQ for NEET Pdf form. These MCQ question on Electromagnetic Waves Class 12 chapter 8  for NEET are based on questions asked in different medical entrance exam like AIIMS, JIPMER, and NEET and other state level medical entrance exam. All Electromagnetic Waves MCQs NEET Questions and Answers in the given below are prepared from previous year papers of all most all entrance exam. We have prepared Electromagnetic Waves (EM waves) MCQs NEET previous year Questions separately. Take a Look Below:

## Important Points to remember about EM waves:

• A wave is a disturbance in a medium that transports energy without causing net particle movement.
• electric current produces magnetic field and that two current-carrying wires exert a magnetic force on each other.
• The most important prediction to emerge from Maxwell’s equations is the existence of electromagnetic waves, which are (coupled) time-varying electric and magnetic fields that propagate in space.
• Two characteristics of electromagnetic radiation are particularly important for understanding remote sensing. These are the wavelength and frequency.
• Electromagnetic waves carry energy as they travel through space and this energy is shared equally by the electric and magnetic fields.
•  Electromagnetic waves transport momentum as well.
• When these waves strike a surface, a pressure is exerted on the surface. If total energy transferred to a surface in time t is U, total momentum delivered to this surface is p = U/c.
• The spectrum of electromagnetic waves stretches, in principle, over an infinite range of wavelengths.
• Different regions are known by different names; γ-rays, X-rays, ultraviolet rays, visible rays, infrared rays, microwaves and radio waves in order of increasing wavelength from 10–2 Å or 10–12 m to 106m.

## Multiple Choice Questions On Electromagnetic Waves (EM waves) with Answer

1.If there were no atmosphere, the average temperature on earth surface would be________

(a) lower

(b) higher

(c) same

(d) 0° C

2. In which part of earth’s atmosphere is the ozone

layer present ?

(a) troposphere

(b) stratosphere

(c) ionosphere

(d) mesosphere

3. The ozone layer is earth’s atmosphere is crucial for human survival because it________

(a) contains ions

(c) reflects ultraviolet rays

(d) reflects infra red rays

4. The frequency from 3 × 10⁹Hz to 3 × 10¹⁰ Hz is __________

(a) high frequency band

(b) super high frequency band

(c) ultra high frequency band

(d) very high frequency band

5. The frequency from 3MHz to 30 MHz is known as_________

(a) audio band

(b) medium frequency band

(c) very high frequency band

(d) high frequency band

6. Select wrong statement from the following for EMW___________

(a) are transverse

(b) travel with same speed in all medium

(c) travel with the speed of light

(d) are produced by accelerating charge

7. The waves related to tele-communication are___________

(a) infrared

(b) visible light

(c) microwaves

(d) ultraviolet rays

8. The nature of electromagnetic wave is________

(a) longitudinal

(b) longitudinal stationary

(c) transverse

(d) transverse stationary

9. What is the cause of greenhouse effect ?

(a) Infrared rays

(b) Ultraviolet rays

(c) X-rays

10. The conduction current is the same as displacement current when source is_______

(a) ac only

(b) dc only

(c) both ac and dc

(d) neither dc nor ac

11. For a wave propagating in a medium, identify the property that is independent of the others ___________

(a) Velocity

(b) Wavelength

(c) Frequency

(d) All these depend on each other

12. Which wavelength of the Sun is used finally as electric energy ?

(b) IR waves

(c) Visible light

(d) Microwaves

13. The condition under which a microwave oven heats up a food item containing water molecules most efficiently is___________

(a) Infra-red waves produce heating in a microwave oven

(b) The frequency of the microwaves must match the resonant frequency of the water molecules

(c) The frequency of the microwaves has no relation with natural frequency of water molecules

(d) Microwaves are heat waves, so always produce heating

14. The sun delivers 10³ w/m2 of electromagnetic flux to the earth’s surface. The total power that is incident on a roof of dimensions 8m × 20m, will be___________

(a) 6.4 × 10³​W

(b) 3.4 × 10⁴​W

(c)1.6 × 10⁵W

(d) none of these

15.In the above problem, the radiation force on ther roof will be__________

(a) 3.33 × 10–⁵ N

(b) 5.33 × 10–⁴ N

(c) 7.33 × 10–³ N

(d) 9.33 × 10–² N

16. Which of the following statement is false for the properties of electromagnetic waves ?

(a) These waves do not require any material medium for propagation

(b) Both electric and magnetic field vectors attain the maxima and minima at the same place and same time

(c) The energy in electromagnetic wave is divided equally between electric and magnetic vectors

(d) Both electric and magnetic field vectors are parallel to each other and perpendicular to the direction of propagation of wave

17. The energy of the em waves is of the order of 15 keV. To which part of the spectrum does it belong?

(a) g-rays

(b) X-rays

(c) Infra-red rays

(d) Ultraviolet rays

18. Greenhouse effect keeps the earth surface _______

(a) cold at night

(b) dusty and cold

(c) warm at night

(d) moist

19. A laser beam is of 9 mW, diameter = 2 mm. Then what is the amplitude of magnetic field associated with it ?

(a) 49 µT

(b) 98 µT

(c) 9.8 µT

(d) 4.9 µT

20. The intensity of sun on earth is 1400 W/m2 Assuming earth to be a black body. Calculate radiation pressure ?

(a) 4.66 × 10⁶ ​N/m2

(b)1.4 × 10–⁶ Nm/2

(c) 4.66 × 10–⁶ N/m2

(d) 7 × 10–⁶ N/m

21. In EMW, E = 50 sin (wt-kx). If m = 4m0 and e = e 0 then average power per unit area is_______________

(a) 1.65 W/m²

(b) 165 W/m²

(c) 16.5 W/m²

(d) 0.165 W/m

22. The pressure exerted by an electromagnetic wave of intensity I W/m² on a non-reflecting surface is_____________

(a) Ic

(b) Ic²

(c) I/c

(d) I/c²

23. A plane electromagnetic wave of frequency 40 MHz travels in free space in the X-direction. At some point and at some instant, the electric field Er has its maximum value of 750 N/C in Y-direction.The wavelength of the wave is ____________

(a)3.5 m

(b) 5.5 mm

(c) 7.5 m

(d) 9.5

24. Which of the following can be used to produce a propagating electromagnetic wave?

(a) Charge moving at a constant speed

(b) Chargeless particle

(c) Stationary charge

(d) An accelerating charge

25. 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_____________

(a) Unity

(b) Speed of light in vacuum

(c) Reciprocal of the speed of light in vacuum

(d) The ratio of magnetic permeability to electrical susceptibility in a vacuum

26. Which properties amount the following is false about electromagnetic waves?

(a) The energy in an electromagnetic wave is divided equally between electric and magnetic vectors.

(b) Both electric and magnetic field vectors are parallel to each other and perpendicular to the direction of propagation of the wave.

(c) These waves do not require any material medium for propagation.

(d) Both electric and magnetic field vectors attain the maxima and minima at the same place and the same time.

27. Modern EDM uses which among the following waves?

(a) Visible rays

(b) Thermal infra-red

(c) Modulated infra-red

28. The distance in EDM is measured by______________

(a) Frequency of the wave

(b) Wave length

(c) Phase difference

(d) Amplitude

29. Electromagnetic waves are represented in which of the following format?

(a) Longitudinal waves

(b) Transverse waves

(c) Sinusoidal waves

(d) Surface waves