EM spectrum

Question 1

How do you make a lens stronger?

Answer 1

Change material
Make it more curved

Question 2

What is the power of a lens related to?

Answer 2

focal length
shape

Question 3

Danger of microwaves?

Answer 3

can cause internal heating of body cells

Question 4

Danger of infrared?

Answer 4

Cause skin burn

Question 5

Danger of UV

Answer 5

lead to skin cancer and skin damage

Question 6

X-ray/gamma

Answer 6

mutations in body cells

Question 7

What are long-wave radio waves

Answer 7

1-10km long
curve around the earth.
Signals can be received even when not in line of sight of the transmitter

Question 8

What are short wave radio signals

Answer 8

10-100m. Can be received long distances, however because they are reflected by the earth’s atmosphere

Question 9

How are radio waves made and received?

Answer 9

Radio waves can be produced by an alternating current. When received by a receiver, the EM waves are absorbed and start an alternating current in the receiver’s circuit. This causes a full circuit.

Question 10

What are the advantages of radio waves

Answer 10

used for satellite communication
used for communications
used for broadcasting

Question 11

use of microwaves

Answer 11

cooking
comms
satellite transmissions

Question 12

use of infrared

Answer 12

monitor temperature
Thermal imaging
cooking
TV remotes
security systems

Question 13

visible light uses

Answer 13

vision
photography

Question 14

UV ray uses

Answer 14

Fluorescent lamps
Security pens
sterilise water

Question 15

X-ray use

Answer 15

internal structure of things

Question 16

Gamma

Answer 16

sterilisation of food and equipment
cancer treatment