Physics

Question 1

What is a system

Answer 1

It is a single object or a group of objects that your interested in

Question 2

What happens when a system changes

Answer 2

It’s energy is transferred. Some energy is dissipated and some stored in less useful ways

Question 3

How can energy be transferred

Answer 3

By heating, by forces doing work and by electrical equipment

Question 4

What is the equation for work done

Answer 4

Work done = force * distance moved

Question 5

What is the equation for power

Answer 5

Power = work done / time taken

Question 6

What does a free body force diagram show

Answer 6

It shows all of the forces acting on an object

Question 7

What happens when an object is at an equilibrium

Answer 7

This means the forces are balanced

Question 8

What is the equation for the moment of a force

Answer 8

Moment of a force = force * distance

Question 9

What is the equation for charge

Answer 9

Charge = current * time

Question 10

What are all the symbols needed for a circuit

Answer 10

Look at page 71 in cgp guide

Question 11

What is the equation for energy transferred

Answer 11

Energy tans ferried = charge moved * volts

Question 12

What’s the equation for potential difference

Answer 12

Voltage = current * resistance

Question 13

What happens when the temperature increases in a circuit

Answer 13

The resistance increased

Question 14

What does an ldr do

Answer 14

It decreases the resistance on a circuit the lighter it gets

Question 15

What does a thermistor do

Answer 15

The resistance decreases as it gets hotter

Question 16

What happens if you add 2 resistors in a series circuit

Answer 16

The resistance is the sum of the resistance of the 2 resistors

Question 17

What happens if you add resistors to parallel circuits

Answer 17

The total resistance becomes less than the smallest resistor

Question 18

What is the equation for energy

Answer 18

Energy = time * volts * current

Question 19

What is the equation for power

Answer 19

Power = energy transferred/ time

Question 20

What is the equation for electrical power

Answer 20

Power = current * potential difference

Question 21

What are the 3 wikres in a cable

Answer 21

Neutral wire - it’s blue and completes the circuit

Live wire - it’s brown and carries the voltage

Earth wire - green and yellow and it’s for safety

Question 22

What does earthing and fuses do

Answer 22

Prevents electrical overloading

Question 23

How is static electricity created

Answer 23

This is when 2 insulating materials are rubbed together, and negatively charged electrons will rub off from one into another.

Question 24

What are uses of static electricity

Answer 24

Photocopiers, paint sprayers and insecticides

Question 25

How can static electricity be dangerous

Answer 25

Refusing cars - as fuel flows out into the fuel tank static builds up. This can lead to explosions. On airaplanes Lightning

Question 26

What happens when a magnetic object goes into the magnetic field of a magnet.

Answer 26

It becomes an induced magnet

Question 27

What happens when there is a current in between 2 magnets

Answer 27

The fields curve with the field of the current until they meet their destined pole

Question 28

What is the equation of force

Answer 28

Force = magnetic flux density * current * length

Question 29

What is a solenoid

Answer 29

A long coil of wire

Question 30

How do you know which way a current carrying coil of wire spins in a magnetic field

Answer 30

Left hand rule (thumb = direction of force, first finger = field and second finger = current.)

Question 31

What is the magnetic field like through an electrically charged solenoid

Answer 31

The field travels all through the coil and then loops back

Question 32

Hat Is electromagnetic induction

Answer 32

The induction of a voltage in a wire expecting a change in magnetic field

Question 33

What do transformers do

Answer 33

They use induction to change the voltage of an alternating current

Question 34

What does a step up and step down transformer do

Answer 34

Step up - increase voltage and could Step down - decrease voltage and coils

Question 35

What is the equation for transformers

Answer 35

Primary voltage * primary current = secondary d.p * secondary I

Question 36

What do Dynamos and alternators do

Answer 36

Dynamos creat dc and alternators creat ac

Question 37

Hat Is the equation for voltage to coils

Answer 37

Input d.p / output p.d = primary coils / secondary coils

Question 38

What is the equation for change in thermal energy

Answer 38

Change in thermal energy = mass * specific heat capacity * temp change

Question 39

What is the temperature of absolute 0

Answer 39

0 kelvin, -273°

Question 40

What’s the freezing point of water

Answer 40

0°c , 273 kelvin

Question 41

What is the equation for force with springs

Answer 41

Force = spring constant * extention

Question 42

Hat Is the equation for fluid pressure

Answer 42

Fluid pressure = height * density of liquid * gravity(10)