Electromagnetic Waves Chapter Test

Willer Academy - Bihar Board Class 12 Physics

Test Instructions

Complete all 20 MCQs and 5 numerical problems. You have 45 minutes.

Time: 45:00

Multiple Choice Questions (20 × 1 mark = 20 marks)

1. Which of the following has the highest frequency?

Radio waves

Microwaves

X-rays

Infrared rays

2. The electromagnetic waves used in satellite communication are:

Radio waves

Microwaves

Infrared waves

Ultraviolet waves

3. Which of the following electromagnetic waves has the shortest wavelength?

Gamma rays

X-rays

Ultraviolet rays

Infrared rays

4. The speed of electromagnetic waves in vacuum is:

3 × 10⁶ m/s

3 × 10⁸ m/s

3 × 10¹⁰ m/s

3 × 10¹² m/s

5. Which of the following is NOT an electromagnetic wave?

Sound wave

Light wave

Radio wave

X-ray

6. The electromagnetic waves used for sterilization of medical instruments are:

Infrared rays

Ultraviolet rays

Radio waves

Microwaves

7. The relation between frequency (f), wavelength (λ), and speed of light (c) is:

c = f/λ

c = fλ

c = λ/f

c = f²λ

8. Which electromagnetic waves are used in remote controls of electronic devices?

Radio waves

Infrared waves

Ultraviolet waves

Gamma rays

9. The electromagnetic waves used in radar systems are:

Radio waves

Microwaves

Infrared waves

X-rays

10. Which of the following has the maximum penetrating power?

Ultraviolet rays

Infrared rays

Gamma rays

X-rays

11. The electromagnetic waves that are absorbed by the ozone layer are:

Infrared rays

Ultraviolet rays

Gamma rays

Radio waves

12. Which electromagnetic waves are used for cancer treatment?

Radio waves

Microwaves

Gamma rays

Visible light

13. The scientist who first predicted the existence of electromagnetic waves was:

Heinrich Hertz

James Clerk Maxwell

Michael Faraday

Isaac Newton

14. The electromagnetic waves used in night vision devices are:

Infrared waves

Ultraviolet waves

Radio waves

X-rays

15. Which of the following electromagnetic waves is visible to the human eye?

Radio waves

Microwaves

Visible light

X-rays

16. The electromagnetic waves used in microwave ovens are:

Radio waves

Microwaves

Infrared waves

Ultraviolet waves

17. Which electromagnetic waves have the longest wavelength?

Gamma rays

X-rays

Radio waves

Ultraviolet rays

18. The electromagnetic waves used in medical imaging (radiography) are:

Radio waves

X-rays

Infrared waves

Microwaves

19. Which of the following statements about electromagnetic waves is FALSE?

They are transverse waves

They can travel through vacuum

They require a medium to propagate

They travel at the speed of light in vacuum

20. The electromagnetic waves used in GPS navigation are:

Radio waves

Microwaves

Infrared waves

Ultraviolet waves

Numerical Problems (5 × 4 marks = 20 marks)

1. Calculate the wavelength of an electromagnetic wave with frequency 15 MHz.

2. The magnetic field in a plane electromagnetic wave is 600 nT. Calculate the amplitude of the electric field.

3. A radio can tune in to any station in the 7.5 MHz to 12 MHz band. What is the corresponding wavelength band?

4. The amplitude of the magnetic field part of a harmonic electromagnetic wave in vacuum is 510 nT. What is the amplitude of the electric field part of the wave?

5. A plane electromagnetic wave has a frequency of 2 × 10¹⁰ Hz. Calculate its wavelength in air.

Test Results

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MCQ Score

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Numerical Score

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