Easter Revision Summary Sheets Paper Two

Question 1

Complete the gap fill :
Magnetic force is a type of ………. force and it is strongest at the ……. Of the magnet. There are two types of magnetic pole: a ……. …….. and a ….. ……

Answer 1

Non-contact
Poles
North Pole
South Pole

Question 2

What is a magnetic field

Answer 2

The region around a magnet where a force acts on another object or on a magnetic material

Question 3

What is a factor that affects the strength of the magnetic field

Answer 3

The strength of the magnetic field depends upon the distance from the magnet

Question 4

List four magnetic materials

Answer 4

Iron
Steel
Nickel
Cobalt

Question 5

What is the difference between a permanent magnet and an induced magnet

Answer 5

Permanent magnets produce their own magnetic field. Induced magnets become a magnet when placed in a magnetic field. However, when removed from the magnetic field an induced magnet loses most/all of its magnetism quickly.

Question 6

How can the direction of a motor be reversed

Answer 6

By reversing the direction of the current or reversing the direction of the magnetic field

Question 7

How can the speed of a motor be increased

Answer 7

By increasing the size of the current or increasing the magnetic field/ use a larger magnet

Question 8

What rule can be used to find the direction of the force

Answer 8

Flemming’s left hand rule

Question 9

What does each part of flemmings left hand rule represent

Answer 9

Thumb(held at 90 degrees)-force/thrust
First finger-field
Second finger-current

Question 10

Why will a motor not work without a commutator

Answer 10

The commutator ensures that the current stays in the same direction, also the coil would not be free to spin. This means the coil would remain still and not rotate

Question 11

What is a solenoid

Answer 11

A solenoid is turned when a long piece of conducting(and insulating) wire is looped into a coiled cylinder

Question 12

How can you find the North Pole of a solenoid

Answer 12

Using the right hand grip method. Hold the solenoid with your right hand and finger pointing in the direction of the current is flowing. Your thumbs should point to the North Pole

Question 13

What is the method that informs you could use to investigate the magnetic field.

Answer 13

Right hand grip method/rule

Question 14

What do your thumb and fingers represent in the right hand grip method/rule

Answer 14

Thumb-direction of current
Fingers-the direction the field lines should be drawn

Question 15

List four ways in which you can make the magnetic field around a solenoid/electromagnet stronger

Answer 15

Use longer current
Use an iron core
Add more turns to the wire
Place the turns of wire close together

Question 16

Describe what happens to the magnetic field around a straight wire when the current is reversed

Answer 16

The magnetic field is also reversed

Question 17

What is the motor effect

Answer 17

If a conductor carrying a current is placed in a magnetic field, the magnet producing the filed and the conductor exert a force on each other

Question 18

Which type of wave are electromagnetic waves

Answer 18

Transverse waves

Question 19

Which part of the EM spectrum can human eyes detect

Answer 19

Visible light only

Question 20

What is the order of the electromagnetic spectrum

Answer 20

Radio waves-micro waves-infrared waves-visible light-ultraviolet waves-x rays-gamma rays

Question 21

Explain radio waves and their uses

Answer 21

Television, radio and Bluetooth
The waves have low energy and so are not harmful for transmitting information over long distances

Question 22

Explain microwaves and their uses

Answer 22

Satellite communication and cooking food
The water in the food absorbers the microwaves and heats up the food. Microwaves also travel in straight lines so are useful in communications

Question 23

Explain infrared waves and their uses

Answer 23

Remote controls, infrared cameras and heaters
Very hot objects might glow, the wires in a toaster and transfer the heat energy to the food

Question 24

Explain visible light and their uses

Answer 24

Optical fibres and photography(cameras)
The light wave is reflected inside of the fibre without being lost and so can carry data over long distances

Question 25

Explain ultraviolet waves and their uses

Answer 25

Security marking, energy efficient lamps and sunbeds
Not visible too the human eye on banknotes and other documents so can help identify counterfeit or stolen goods

Question 26

Explain x-rays and their uses

Answer 26

Medical imaging and medical treatment
X rays penetrate soft tissues but not through bones so an image can be formed

Question 27

Explain gamma rays and their uses

Answer 27

Medical treatment for cancer and sterilising food
Higher frequency of all EM waves so will pass through plastic wrapping and metals to kill bacteria. Also kills cancer cells

Question 28

Which type of EM wave has the longest wavelength

Answer 28

Radio waves

Question 29

EM wave with highest frequency

Answer 29

Gamma rays

Question 30

EM waves with shortest wavelength

Answer 30

Gamma rays

Question 31

EM wave with lowest frequency

Answer 31

Radio wave

Question 32

EM wave with most energy

Answer 32

Gamma rays

Question 33

EM wave with least energy

Answer 33

Radio wave

Question 34

Which type of EM wave can be produced by oscillations in electrical circuits

Answer 34

Radio waves

Question 35

What can these radio waves also induce in electrical circuits

Answer 35

Oscillations

Question 36

State four factors that are affected by different substance interacting with different EM waves

Answer 36

Absorbption
Reflection
Refraction
Transmitted