14) Electromagnetic Waves

Question 1

what is the speed of light in vacuum?

Answer 1

3x10^8 m/s

Question 2

can you name one electromagnetic wave?

Answer 2

name any one:

radio waves, microwaves, infrared (IR), visible light, ultraviolet (UV), X-rays and gamma rays.

Question 3

How are the electromagnetic waves arranged?

Answer 3

In order of increasing or decreasing wavelength or

in order of increasing or decreasing frequency

Question 4

Which wave has the longest wavelength?

Answer 4

radiowave

Question 5

Which wave has the highest frequency?

Answer 5

gamma ray

Question 6

which wave has the lowest frequency?

Answer 6

radiowaves

Question 7

State all 7 components of the electromagnetic spectrum in increasing order of wavelength.

Answer 7

In this order:

gamma rays, X-rays, ultraviolet, visible light, infrared, microwaves and radio waves.

Question 8

State one application of radio waves.

Answer 8

radio and television communication to transmit sound and pictures

Question 9

State one application of microwaves.

Answer 9

satellite communication, mobile phone network, cooking food in a microwave oven

Question 10

State one application of infra-red.

Answer 10

used in thermal imaging cameras, surveillance system to detect intruders, transmit information in remote controls.

Question 11

State one application of visible light.

Answer 11

used in lasers to cut through hard materials or weld metals together, allows humans to see

Question 12

State one application of ultraviolet rays.

Answer 12

stimulates the body to produce vitamin D, sterilise surgical equipment, used in anti-forgery in currencies

Question 13

State one application of X-rays.

Answer 13

used to examine hidden flaws and cracks in metal welding, inspection of luggage in airports, examine the condition of a person’s bones

Question 14

State one application of gamma rays.

Answer 14

used to kill cancerous cells, sterilise hospital equipment, check flaws in metal