Light and the EM spectrum

Question 1

what abbreviation do we use to remember the colours of the rainbow?

Answer 1

ROYGBIV

Question 2

what colour in the rainbow has the longest wavelength and lowest frequency?

Answer 2

red

Question 3

what colour in the rainbow has the shortest wavelength and the highest frequency?

Answer 3

Violet

Question 4

what determines the colour of an object?

Answer 4

The colour of an object is determined on the wavelength of light hitting the object and what colours it reflects.
For example, a red cat only reflects the red wavelength

Question 5

what is an opaque object?

Answer 5

An opaque object is an object which doesn’t transmit any light and therefore either absorbs or reflects light. the reflect colours of the ones that we see any solid object which you can’t see through is an opaque object and reflects the colour you see

Question 6

In terms of colour what is white made up of?

Answer 6

White is made up of all of the colours combined

Question 7

in terms of colour what is black made up of?

Answer 7

Black is the absence of all colour

Question 8

In terms of wavelength, why can we see through a transparent object?

Answer 8

Transparent objects such as glass windows transmit nearly all lights and therefore only a small fraction is absorbed or reflected and therefore we can see straight through it

Question 9

in terms of wavelength, describe how translucent objects are the way they are

Answer 9

Translucent objects transmit only a small amount of light (the amount of transmitted light determines how well we can see through it) the rest is either reflected or absorbed. This is why translucent objects are not fully see-through.

Question 10

describe how primary colour filters work

Answer 10

any light that is shined through a primary colour filter but only reflect its colour. For example if white light is shining through a red colour filter only red light will pass through.

Question 11

What electromagnetic wave has the longest wavelength and lowest frequency?

Answer 11

Radio waves

Question 12

what electromagnetic wave has the shortest wavelength and the highest frequency?

Answer 12

Gamma waves

Question 13

What are radio waves used for?

Answer 13

Radio waves are used for transmitting radio radio broadcasts and TV programs as well as other communications.

Some radio communications are sent via satellite

Question 14

How the radio waves communicate via antenna

Answer 14

A transmitting antenna has a Ating current which creates a magnetic field. This then attracts radio waves which due to the alternating current produce oscillations these oscillations travel at the speed of light and absorbed by the receiving antenna.

Question 15

What are the dangers of radio waves?

Answer 15

Exposure to high intensity of radio waves can result in the heating of biological tissue and an increased

Question 16

What’s a microwaves used for?

Answer 16

Microwaves are used for communications and satellite transmissions including mobile phone signals. In a microwave oven microwaves transfer energy to food heating it up from the inside.

Question 17

What are the dangers of microwaves?

Answer 17

Exposure to microwaves can cause skin burns

Question 18

what are the uses for infrared radiation?

Answer 18

Infrared radiation can be used for communication at short ranges such as between a TV and a remote or two computers in the same room.

a grill or toaster transfers energy to food by infrared radiation. The food absorbs the radiation and heats up. thermal imaging cameras show the amount of infrared radiation in a room

Security systems often have sensors that can detect infrared radiation emmited by intruders