Extras

Question 1

What do simple levers make it easier to do

Answer 1

Easier to do work by moving the distance the force is applied further from the pivot

Question 2

Where are pendulums used

Answer 2

Clocks, playground swings, fairground rides

Question 3

What is cross section area in a hydraulic measured in

Answer 3

M^2

Question 4

What is velocity

Answer 4

Both the speed and direction of an object

Question 5

Example of a centripetal force using friction

Answer 5

A car going round a bend.

Friction between the cars tyres and the road

Question 6

What can magnetic fields be represented by

Answer 6

Field diagrams - the arrows on them always pint from North Pole to the South Pole

Question 7

What is a magnetic field made up of

Answer 7

Concentrated circles with the wire in the centre

Question 8

How to work out which way the magnetic field is going around a wire

Answer 8

The right hand thumb rule where you curl your hand and your thumb points the way of the current and the direction your fingers are curled shows the direction of the field

Question 9

How can you increase the strength of the magnetic field around a coil of wire (a solenoid)

Answer 9

Adding a magnetically soft iron core through the middle of the coil (an electromagnet is formed)

Question 10

What are electromagnets used in

Answer 10

Electric bells, car ignition circuits and some security doors

Question 11

What way does current flow usually

Answer 11

From +ve to -ve

Question 12

What does electric motors use the motor effect for

Answer 12

To get them and keep them moving

Question 13

How do electric motors help make CD players, food mixers, fan heaters, fans, printers, drills, hair dryers, cement mixers work

Answer 13

Link the coil to an axle and the axle spins round.
This can be attached to a fan, a blade or whisk, the bit you sit the cd on.
Fan heaters and hair dryers have an electric heater as well as a fan.

Question 14

Why will a freely suspended object swing until it’s centre of mass is vertically below the point of suspension

Answer 14

Objects weight acts at a distance from the pivot which creates a moment around the pivot so it swings.
Until centre of mass is at its lowest then it rests in this position because there’s no moment.
The pivot is in line with the line of action of the force.

Question 15

What is the wiring to a three pun plug

Answer 15

• the right coloured wire is connected to each pin and firmly screwed
• no bare wires in the plug
• cable grip tightly fastened over the cable outer layer
• depending on the appliance have the right cable size because thicker cables have less resistance so they carry more current

Question 16

Why are parts of the plug made of metal like copper and brass

Answer 16

Because they are good conductors

Question 17

What are two important effects of gravity

Answer 17

Gives everything a weight

Makes everything accelerate towards the ground

Question 18

What is weight measured using

Answer 18

A sprint balance or Newton metre as its in newtons

Question 19

What is mass measured using

Answer 19

A mass balance as its in Kg

Question 20

What is the gravity on the moon

Answer 20

1.6 N/kg

Question 21

What is an example of a circuit breaker

Answer 21

Residual current circuit breaker

RCCB

Question 22

How do RCCBs operate

Answer 22

Detecting a different in he current between the live and neutral wire

Question 23

If an appliance is double insulated what does this mean

Answer 23

It has no earth wire connection - only metal cased ones do

Question 24

What is extension of a spring measured by

Answer 24

Metres

Question 25

What is the limit of proportionality

Answer 25

The maximum force an elastic object can take and still extend proportionately

Question 26

What is momentum

Answer 26

The property of moving objects

Question 27

What is a closed system

Answer 27

No external forces are acting on it

Question 28

What is the conservation of momentum

Answer 28

The total momentum before is the total momentum after

Question 29

How do u find velocity in the momentum

Answer 29

Chose which direction is positive Find total momentum before collision - the one who is going in the negative way will have a minus force And then if the tmb = tma you can work out the velocity

Question 30

What does aerodynamic mean

Answer 30

They are shaped in such a way that air flows very easily and smoothly past them

Question 31

If the resistance in a component increases what happens to the current

Answer 31

The smaller the current that flows

Question 32

By varying the variable resistor what happens

Answer 32

It alters the current letting you take several pairs of readings from the A and V

Question 33

What is a diode made of and what is it used for

Answer 33

Semiconductor material such as silicon and to regulate the potential difference. Useful in electronic circuits

Question 34

Why are led used a lot

Answer 34

They use a smaller current than other forms of lighting

Question 35

Where are thermistors used

Answer 35

Car engine temperature sensors, electronic thermostats

Question 36

How to work out current in a series circuit

Answer 36

Total voltage divided by resistance

Question 37

What is electric current

Answer 37

The movement of charge carriers

Question 38

What does the gain dial control

Answer 38

How many volts each centimetre division represents on the vertical axis

Question 39

What does the time base dial control

Answer 39

How many milliseconds each division represents on the horizontal axis

Question 40

When do cuss ratings needed for cables increase

Answer 40

With cable thickness

Question 41

What are cables known as that only carry the live and neutral wire

Answer 41

Two core cables

Question 42

How do filament bulbs work

Answer 42

Passing a current through a very thin wire heating it up so it glows

Question 43

How to work out power rating of appliances

Answer 43

Energy transferred divided by time

Question 44

What experiment did Rutherford and marsden do

Answer 44

They beamed alpha particles at a thin sheet of gold foil expecting them to be slightly deflected but most went straight back through and a few shot completely back. Realised most of mass in nucleus and atom was empty space.

Question 45

What is half life

Answer 45

The average time it takes for half the number bed of nuclei in a radioactive isotope sample to halve

Question 46

What is radiotherapy

Answer 46

Treatment of cancer using gamma rays

Question 47

How can X-ray images be formed electronically

Answer 47

Using charged coupled devices (CCDs)

Question 48

How do CCDs work

Answer 48

They are silicon chips the size of a postage stamp. They detect X-rays and produce electronic signals which are used for high resolution images like in s camera

Question 49

When working out the power of the two lenses which was is negative and which is positive

Answer 49

Negative is diverging | Positive is converging

Question 50

What are lasers used to treat besides eyes and cauterising wounds

Answer 50

Treating skin conditions like acne scars they can burn off the top layers of scarred skin

Question 51

What can optical fibres carry

Answer 51

Visible light over long distances

Question 52

In an endoscope where can the image be seen

Answer 52

Through an eyepiece or displayed as a full colour moving image on a screen

Question 53

In a symmetrical shape hoe do you find the centre of mass

Answer 53

The lines of symmetry

Question 54

How do generators work

Answer 54

Turning a magnet end to end in a coil to create a current that lasts as long as YOY spin the magnet

Question 55

What do step up transformers do

Answer 55

Step the voltage up

Question 56

What do step down transformers do

Answer 56

Step the voltages down

Question 57

What is a load in a switch mode transformer

Answer 57

The thing you're charging or powering

Question 58

Why are switch mode transformers good

Answer 58

Efficient. | They use little power when they're switch on and no load is applied e.g no phone in phone charger