1. Electromagnetic waves are
Answer: C. transverse waves
Physics Class 10 Unit 20: Electromagnetic Waves MCQs
64 multiple choice questions with the correct answer for each. Tap an option to check yourself, or switch on "Show all answers". This is page 1 of 2.
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2. Electromagnetic waves
Answer: B. do not require a medium for propagation
3. The range of different frequencies and wavelengths of electromagnetic waves is called the
Answer: D. electromagnetic spectrum
4. The correct order of EM waves from the longest wavelength to the shortest is
Answer: A. radio, microwave, infrared, visible, ultraviolet, X-rays, gamma rays
5. The speed of all electromagnetic waves in vacuum is
Answer: B. 3×108 m/s
6. Which EM waves have the longest wavelength?
Answer: A. Radio waves
7. The energy of a photon is given by
Answer: C. E = hf
8. The constant h in E = hf is called
Answer: D. Planck's constant
9. The value of Planck's constant is
Answer: D. 6.63×10-34 J s
10. The energy of an electromagnetic wave depends directly on its
Answer: B. frequency
11. The relation between energy and wavelength is
Answer: A. E = hc/λ
12. The wavelength of an EM wave of frequency 5.0×1014 Hz is
Answer: C. 600 nm
13. A wave of wavelength 10 cm belongs to
Answer: A. microwaves
14. X-rays have higher energy than visible light because of their
Answer: D. shorter wavelength
15. When an EM wave enters another medium, the quantity that does not change is
Answer: B. frequency
16. Electromagnetic waves are produced by
Answer: C. accelerating charged particles
17. One electron-volt (eV) is equal to
Answer: D. 1.6×10-19 J
18. The energy of a radiation of wavelength 200 nm is about
Answer: A. 9.945×10-19 J
19. The momentum of a photon of wavelength 200 nm is about
Answer: B. 3.315×10-27 kg m/s
20. A radiation of energy 4.7 eV has wavelength about 265 nm and belongs to
Answer: C. ultraviolet
21. Radio waves are used in
Answer: B. television, mobile phones and wireless networks
22. The study of radio waves from space is called
Answer: C. radio astronomy
23. Radio telescopes need to be very large because radio waves have
Answer: A. much longer wavelengths than visible light
24. Satellite TV communication uses
Answer: D. microwaves
25. Microwaves are used for satellite communication because they can
Answer: C. pass easily through the atmosphere
26. A typical microwave oven uses a frequency of
Answer: B. 2.45 GHz
27. Microwaves cook food by making ______ molecules vibrate.
Answer: A. water
28. Infrared means
Answer: D. below red
29. Infrared radiation is used in
Answer: B. remote controllers
30. The type of radiation which primarily carries heat energy is
Answer: C. infrared
31. Waves used for treating muscle aches in physiotherapy are
Answer: D. infrared
32. The Sun has a surface temperature of about
Answer: A. 6000 K
33. UV-A has wavelengths of about
Answer: C. 320 to 400 nm
34. Most UV-B and all UV-C radiation is absorbed by the
Answer: A. ozone layer
35. About ______ of solar UV reaching Earth's surface is UV-A.
Answer: B. 99 %
36. Counterfeit bank notes can be detected using
Answer: D. ultraviolet light
37. UV light is used for sterilising
Answer: C. water
38. X-rays are widely used for
Answer: B. medical imaging of bones
39. The use of X-rays in medical science is called
Answer: A. radiology
40. X-ray security scanners are used to detect
Answer: D. weapons or explosives under clothing
41. X-rays and gamma rays are used in radiographic testing to detect
Answer: B. cracks in metals
42. At high doses, X-rays or gamma radiation therapy kills cancer cells by damaging their
Answer: C. DNA
43. Gamma rays are emitted from the
Answer: A. nucleus of a heavy atom
44. The radioactive isotope commonly used for sterilising food and medical equipment is
Answer: D. Cobalt-60
45. Food sterilised with gamma rays
Answer: B. does not become radioactive
46. Ionizing radiation includes
Answer: D. UV, X-rays and gamma rays
47. Non-ionizing radiation includes
Answer: A. visible light, infrared, microwaves and radio waves
48. Long-term exposure to UV waves can cause
Answer: C. skin cancer
49. Protection from ionizing radiation includes shielding, limiting exposure time and
Answer: C. maintaining a safe distance
50. Shorter wavelengths of light scatter
Answer: A. more
About Physics Class 10 Unit 20 MCQs (Federal Board)
These 64 Physics MCQs cover Class 10 Unit 20: Electromagnetic Waves of the Federal Board (FBISE) SSC-II (Class 10) syllabus. They are SLO-based MCQs as per the new pattern for FBISE exams. Each question has four options and the correct answer is shown, so you can practise for the annual examination and find the topics you still need to revise. The questions are split over 2 pages of 50. You can also read the Electromagnetic Waves notes for this chapter. Download the Electromagnetic Waves MCQs as a PDF using the button at the top of this page.