C4 Motor Effect

Question 1

Define the Motor Effect

Answer 1

When a wire carrying a current interacts with another magnetic field, at right angles, causing a force that moves the wire.

Question 2

List 3 ways to increase the force of a motor effect

Answer 2

• the current in the wire increases;
• the strength of the magnetic field increases;
• the length of wire inside the magnetic field is increased.

Question 3

What is a Direct Current?

Answer 3

The flow of charge is going in 1 direction only

Question 4

What is Alternating Current?

Answer 4

The flow of charge is going in both directions

Question 5

Is mains power supply A.C or D.C?

Answer 5

A.C (Alternating Current)

Question 6

What voltage is mains electricity?

Answer 6

230 Volts

Question 7

What Frequency is mains electricity?

Answer 7

50 Hz

Question 8

How can you change the direction a coil is moving in a motor?

Answer 8

• reversing the direction of the current OR
• reversing the direction of the magnetic field (changing over the north and south poles).

Question 9

List 2 way you can increase the speed in a motor?

Answer 9

• increasing the size of the current;
  -using a stronger magnet;
• increasing the number of turns of wire in the coil;
• reducing friction between the coil and the axel it rotates on.

Question 10

What 3 materials are induced magnets made out of?

Answer 10

Iron, Nickel, Cobalt

Question 11

How can you induce an induced magnet?

Answer 11

Put it in the presence of a permeant magnet.

Question 12

True of False: A permeant magnet will always experience attraction when in presence of a induced magnet.

Answer 12

True

Question 13

List 2 ways to increase the strength of an electromagnet.

Answer 13

• Add an iron core
• Increase current

Question 14

What is a solenoid?

Answer 14

The coil of wire surrounding an iron core

Question 15

List 3 examples of electromagnetic radiation

Answer 15

Any of:
- Radiowaves (VHF, UHF)
- Microwaves
- UV Waves
- X-Rays
- IR Radiation
-

Question 16

How many cells make up a battery?

Answer 16

2

Question 17

List a type of an A.C generator

Answer 17

Any of:
- Alternator (Synchronous Generators)
- Induction (Asynchronous Generators)
- Single Phase (Permanant Magnet Alternator)

Question 18

What is the equation for an A.C generator current-time graph?

Answer 18

Any of:
- (y=x^{2}+3x)
- y = x^2 + 3x

Question 19

What is mutual induction?

Answer 19

Mutual induction is where a change in the electric current in one coil (the primary coil) induces a voltage in a nearby coil (the secondary coil)

Question 20

True of False: Mutual Induction can only occur in electromagnets with an A.C power supply

Answer 20

False

Question 21

When a solenoid experienced static electricity, what effect with this have on the current?

Answer 21

The current will become negative causing a change in direction with the current.

Question 22

Does a step up transformer increase or decrease current?

Answer 22

Decrease

Question 23

Does a step down transformer increase or decrease potential difference?

Answer 23

Decrease

Question 24

Is the potential difference in a pylon high or low?

Answer 24

Extremely high

Question 25

Is the current in a pylon high or low?

Answer 25

Low

Question 26

Fill in the gap: Metals conduct electricity due to _________ electrons.

Answer 26

Delocalised