Electromagnetic Spectrum – LearnITbyTests

1. In electromagnetic waves, the energy in the wave is computed by the formula E = hf where: h = plancks constant ( 6.63 x 10 power of -34 Js) and F= frequency of the wave. True or False?

True

False

Maybe

None

Question 1 of 21

2. Mention the some of the hazards of electromagnetic waves

Ultraviolet rays, X-rays and Gamma rays when absorbed into human body in large doses may cause damage to body cells, skin burns and affect the eyes.

Radio waves lead to disruption and high noise levels

Microwaves lead to spoiling of food

All of the above

Question 2 of 21

3. Which of the following is a beneficial use of Radio waves?

Medium and short wavelength radio waves are used in radio transmission signals

Very high frequency are used in V.H.F radios to transmit and receive over short distance

Shorter wavelengths are used for television broadcasts

All of the above

Question 3 of 21

4. Which of the following is NOT a beneficial use of Ultraviolet radiation?

Used in minerals analysis

Cause malignant mutations in the skin (melanoma)

Used to detect forgeries

Used to kill bacteria and skin treatment

Question 4 of 21

5. Electromagnetic waves are transverse waves which result from oscillating electric and magnetic fields at right angles to each other. True or False?

False

True

Maybe

None

Question 5 of 21

6. Which electromagnetic wave is produced as a result of large energy changes in the electrons of an atom?

Ultra violet radiation

Visible light

Infrared radiation

X-rays

Question 6 of 21

7. Which of the following is NOT a beneficial use of Gamma rays?

Cause ionization and mutation in cells

Sterilizing medical equipment

Killing cancerous and malignant growth in human body

To detect flaws in metals in industries

Question 7 of 21

8. State the energy formula of electromagnetic waves

E = m x c x c

E =hf

E =f x lambda

None

Question 8 of 21

9. Which of the following is an example of electromagnetic waves?

Light rays

Ultraviolet

Infrared

All of the above

Question 9 of 21

10. Which of the following is a beneficial use of X-rays?

X-rays are capable of killing malignant tissues

Controlling pests and germs by irradiation

Detect flaws in metals and forgeries in art

All of the above

Question 10 of 21

11. Which of the following statement is TRUE about Radio waves?

They have the longest wavelength within the electromagnetic spectrum

Radio waves are produced by oscillating electrical circuits and transmitted through antennas (aerials)

Radio waves are detected by resonant circuits in radio receivers

All of the above

Question 11 of 21

12. Which of the following statements is TRUE about Ultraviolet Radiation (U.V)

U.V is produced by the sun, sparks and mercury vapor lamps and is generated as a result of large energy changes in the electrons of an atom

No idea

U.V is produced Cathode Ray Tubes

U.V rays are invisible but detectable by photocells, photographic films and fluorescent materials

Question 12 of 21

13. Which electromagnetic wave is produced as a result of small energy changes in the electrons of an atom?

Visible light

Ultra violet radiation

Infrared radiation

X-rays

Question 13 of 21

14. Which of the following statements about Gamma rays is CORRECT?

Gamma rays are emitted by radioactive substances

Gamma rays result from energy changes occurring in the nucleus of radioactive atoms

Gamma rays are detected by photographic plates and radiation detectors

All of the above

Question 14 of 21

15. Which of the following statements is NOT TRUE about Infrared Radiation

Infrared radiation is produced as a result of small energy changes of an electron in an atom and are produced by any hot body

Infrared radiation is produced by the sun only

Infrared radiation is detectable by skin, thermopile, bolometer and thermometer with blackened bulb

Infrared radiation has a longer wavelength than U.V

Question 15 of 21

16. Mention 3 properties of electromagnetic waves

They travel through space (vacuum) with the speed of light (3.0 x 10 power of 8)

They are transverse waves in nature

They undergo interference, reflection, diffraction, refraction and polarization effects.

All of the above

Question 16 of 21

17. Which of the following statements about X-rays is CORRECT?

X-rays are carried in X-ray tubes

X-rays originate from a beam of fast moving electrons hitting a metal target

X-rays are detected by using a fluorescent screen or photographic film

all of the above

Question 17 of 21

18. Mention 2 electromagnetic waves produced by the sun

Radiowaves

Infrared radiation

Ultraviolet radiation

red light lens

Question 18 of 21

19. Define electromagnetic spectrum

It is an arrangement of electromagnetic waves in order.

It is an arrangement of electromagnetic waves arranged in order of wavelengths.

It is an array of electromagnetic waves in order of wavelengths and frequencies.

None

Question 19 of 21

20. Which electromagnetic wave is produced by magnetrons?

X-rays

Microwaves

Visible light

Radio waves

Question 20 of 21

21. Which of the following is NOT a beneficial use of infrared radiation?

Causes heating effect therefore used in cooking, heating and drying

Used to warm greenhouses

Contribute to the GreenHouse Effect

Used in infrared photography

Question 21 of 21

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