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Question 1

Magnetic field

Answer 1

A region magnetic objects have around them where the magnetic force can be felt.

Question 2

The 3 magnetic elements at room temperature:

Answer 2

Iron(Fe)
Nickel(Ni)
Cobalt(Co)

Question 3

Steel is made of what

Answer 3

C + Fe

Question 4

What does sulphur do when bound with iron

Answer 4

Removes its magnetism as it becomes iron sulphide

Question 5

North Pole on a magnet:

Answer 5

North seeking

Question 6

South Pole on a magnet:

Answer 6

South seeking

Question 7

North and south poles can __________…

Answer 7

Interact with eachother or put force on eachother

Question 8

Like poles

Answer 8

Repel

Question 9

Unlike poles

Answer 9

Attract

Question 10

The arrows on a magnetic field bar magnet diagram show what

Answer 10

The force feels if another North Pole was there

Question 11

When two north poles are next to eachother in the centre is

Answer 11

A neutral point of no magnetic force due to the fields cancelling eachother out (destructive interference)

Question 12

When a north and a South Pole are next to eachother

Answer 12

Lots of parallel lines of flux so high flux density so the field strength is strong. It is also constant

Question 13

Why does the earth have its own magnetic field?

Answer 13

Because the core is made of iron

Question 14

Where is the earths magnetic field weakest

Answer 14

Along the equator

Question 15

The earths magnetic field does what to protect us from the sun

Answer 15

It deflects the suns’ rays

Question 16

What can an EM do that a normal magnet can’t?

Answer 16

Have its magnetism switched on or off

Question 17

How to make an EM

Answer 17

Soft magnetic core (soft iron/pure iron)

Wrapped in current carrying wire to create and EM

Question 18

Another name for an EM

Answer 18

A solenoid

Question 19

How to turn an EM on

Answer 19

Apply DC current through the coil. This aligns the domains

Question 20

How to turn an EM off

Answer 20

You can’t just turn off the DC current as there will still be residual magnetism so we apply AC current to unaligned the domains and demagnetise it

Question 21

How to increase an EM’s strength

Answer 21

More coils per unit length
Increase current input
Choose a core with a higher permeance

Question 22

Permeance

Answer 22

The ability of an object to accept or amplify a magnetic field

Question 23

How many times does AC current change direction from the plugs?

Answer 23

About 50 times per second, 50Hz

Question 24

Uses of an EM

Answer 24

Electric doors
Fire bells
Train joins
Hover boards
MRI scans
DC motors
Generators
Speakers
Doorbells

Question 25

Motors’ energy transfer:

Answer 25

El to ke

Question 26

How does a DC motor work

Answer 26

See book for diagram etc.

Question 27

How to reverse the spin of a DC motor

Answer 27

Make the current flow in the opposite direction round the circuit Or reverse the permanent magnet

Question 28

Graph- physics

Answer 28

Title- A graph showing the ... X axis- independent Y axis- dependant

Question 29

Increase the rate of spin for a DC motor

Answer 29

Increase the voltage which increases the current which increases the magnetic field which increases the forces and therefore makes it spin faster

Question 30

Another name for a generator

Answer 30

A dynamo

Question 31

Generator energy transfer

Answer 31

Ke to EL

Question 32

Generator can be described as what

Answer 32

A motor in reverse

Question 33

Electromagnetic induction

Answer 33

process of moving a magnet into a coil of wire to produce a volatage

Question 34

Faraday’s law

Answer 34

States that potential difference is induced across a wire producing electric current when a coil of current carryon wire cuts through a magnetic field or a magnetic field is cut through a coil of wire

Question 35

To increase induced voltage

Answer 35

Increase spin speed | Increase coils per unit length

Question 36

Hydro

Answer 36

Situated in rivers. Water flows downstream pushed through the dam and spins turbines maximises on GPE GPE ke el

Question 37

Tidal

Answer 37

Tidal barrage- Dam structure created sea tide passes under it and sound turbines Gpe ke el

Question 38

Wind

Answer 38

Onshore and offshore Wind turns big turbine Ke el

Question 39

Nuclear

Answer 39

235 uranium or 239 plutonium nuclei absorb a neutron setting off a chain reaction of the nuclei splitting 3 neutrons being released and energy being released. The thermal energy heats up water and turns to gas which spins a turbine Nu th ke el

Question 40

Geo thermal

Answer 40

In volcanic active areas hot rocks under the crust. When they decay steam rises and spins turbines else water poured down and is heated and turned into steam Th ke el

Question 41

Wave

Answer 41

The movement of seawater in and out of a cavity on the shore compresses trapped air, driving a turbine. Ke el

Question 42

Biomass

Answer 42

Burning dead organic matter (wood, ethanol, plants etc.) | Th el

Question 43

Solar

Answer 43

Photovoltaic cells light energy is absorbed by the pc cells. Uses difference in conductivity between the silicon in it to generate a voltage Solar power tower- light and heat from the sun is reflected from the mirrors up to a solar collector. Heat boils water etc. Nuc th ke el

Question 44

Sankey diagrams show what

Answer 44

Energy transfers useful and wasted energy

Question 45

Sankey diagrams’ thickness shows

Answer 45

The amount of energy

Question 46

Kettles waste little amounts of energy because

Answer 46

Insulated | Anchored base to stop movement

Question 47

Energy = | kWh

Answer 47

Power x time | kW. Hrs

Question 48

Cost of energy = | p

Answer 48

Energy used x cost per kWh kWh. P/kWh

Question 49

Filament lamp-

Answer 49

Creates light by pushing current through a wire which gets hot and glows releasing light

Question 50

Filament

Answer 50

Wire of tungsten

Question 51

Lamp in circuit

Answer 51

X in a circle

Question 52

Variable supply (power)

Answer 52

Circle then arrow pointing diagonally up right then circle

Question 53

Ammeter symbol

Answer 53

A in a circle

Question 54

Voltmeter symbol

Answer 54

V in a circle

Question 55

Ohms law

Answer 55

Resistance | Ohms