P2 (physics)(book)

Question 1

What do opposites charges do ?

Answer 1

Opposite charges attract

Question 2

What do like charges do ?

Answer 2

Like charges repel

Question 3

How can static electricity be produced?

Answer 3

Can be produced by rubbing two insulators together

Question 4

What is static electricity the build up of & why is it called static?

Answer 4

It is the build up of charge
It is called static because the charge cant move

Question 5

What can conductors do?

Answer 5

They can conduct electricity

Question 6

What cant insulators do?

Answer 6

They cannot conduct electricity

Question 7

What are needed in order for current to flow?

Answer 7

Power source
Conducting material
Closed circuit

Question 8

What is electric current?

Answer 8

The rate of flow of charge

Question 9

What is current ?

Answer 9

It is how much of something in one second
the rate at which electrons flow past a point in a complete electrical circuit

Question 10

What is charge measured in?

Answer 10

Coulomb

Question 11

Define amps

Answer 11

Amps= coulombs per second
1A = 1 coulomb ÷ second

Question 12

State the equation for charge

Answer 12

Charge = current x time
Q = I x t

Question 13

What is voltage measured in?

Answer 13

Volts

Question 14

What is an ammeter measured in?

Answer 14

Amps

Question 15

What is resistance measured in?

Answer 15

Ohms , Ω

Question 16

Write the equation to calculate the voltage?

Answer 16

V = I x R

Question 17

What is current directly proportional to?

Answer 17

The voltage

Question 18

If v doubles what happens to I ?

Answer 18

I doubles

Question 19

If V halves what happens to I ?

Answer 19

I halves

Question 20

In a parallel circuit what does the current do between branches?

Answer 20

The current is spilt between branches

Question 21

What is the voltage like across each branch in a parallel circuit?

Answer 21

The voltage is the same across each branch

Question 22

What is the I like in a series circuit?

Answer 22

I is the same everywhere in the circuit

Question 23

What is the v like in a series circuit?

Answer 23

V of the cell / battery is shared between components

Question 24

What is resistance caused by?

Answer 24

Resistance is caused by collisions between flowing electrons and positive metal ions (fixed , vibrating in place)

Question 25

What happens to the current, if the resistance of a circuit increases?

Answer 25

Current decreases

Question 26

What is ohms law?

Answer 26

A line goes through proportionally through the origin Current (I) is directly proportional to v (voltage) as long as the temperature is constant

Question 27

A positive ballon is rubbed on a negative jumper and becomes charged. Explain how this happens?

Answer 27

Electrons are transferred through friction

Question 28

Describe and explain how increasing the length of a Wire affects its resistance

Answer 28

The longer the wire the longer the resistance Resistance is caused by collisions between flowing electrons and positive metal ions In a longer wire these collisions are more frequent

Question 29

What does the filament bulb not obey?

Answer 29

Ohm’s law

Question 30

As the potential difference increase what happens to the current in a filament bulb?

Answer 30

Current also increases

Question 31

Higher voltage means higher what in a filament bulb

Answer 31

Higher resistance

Question 32

What happens to the filament as more current flows & why is that?

Answer 32

The filament bulb gets hotter Metal ions gain energy and vibrate faster causing more frequent collisions

Question 33

Why is a variable resistor used?

Answer 33

To get a range of value for the voltage

Question 34

Current flows from what to what?

Answer 34

Current flows from positive to negative

Question 35

What does the component diode do?

Answer 35

It allows the current to flow in one direction

Question 36

Define alternating current

Answer 36

The current changes direction continuously

Question 37

What is the voltage of main electricity?

Answer 37

230V

Question 38

What is the frequency of main electricity?

Answer 38

50Hz

Question 39

What does the fuse prevent?

Answer 39

It prevents too much current going through it so it doesn’t overheat When it does a wire inside the fuse melts so no current and flow

Question 40

What is the function of an earth wire?

Answer 40

To carry charge away from a live casing For safety: to avoid an electrical shock from a metal casing becoming charged

Question 41

What is voltage?

Answer 41

Potential difference is how much joules are added to each coulomb of charge

Question 42

State the equation for electrical work done

Answer 42

E = Q x V Electrical work done = charge x potential difference (J) = (c) x (v) E=P x t

Question 43

Define power

Answer 43

Rate of energy transfer

Question 44

Define national grid

Answer 44

System of transformers and cables

Question 45

What happens at the step up transformer?

Answer 45

Increases the voltage Lowers the current So the wire doesn’t overheat So less energy is dissipated

Question 46

What happens at the step down transformer?

Answer 46

Lower the voltage Increase current

Question 47

What does ∝ mean?

Answer 47

Directly proportional

Question 48

What does AC stand for?

Answer 48

Alternating current

Question 49

What particle carries the charge in an electric circuit?

Answer 49

The electron

Question 50

How do you connect an ammeter to a circuit, in parallel or in series ?

Answer 50

In series

Question 51

How do you connect a voltmeter to a circuit, in parallel or in series?

Answer 51

In parallel

Question 52

What does a voltmeter measure?

Answer 52

A potential difference or voltage

Question 53

Name the 2 non-ohmic components?

Answer 53

Filament bulb Diode

Question 54

What happens to the resistance of an LDR as the light intensity increases?

Answer 54

It decreases

Question 55

What happens to the resistance of a thermistor as the temperature increases?

Answer 55

It decreases

Question 56

What colour is the live wire on a 3-pin UK plug?

Answer 56

Brown

Question 57

What colour is the neutral wire in 3-pin uk plug?

Answer 57

Blue

Question 58

What colour is the earth wire in 3 pin uk plug?

Answer 58

Striped yellow ans green

Question 59

What is the voltage in the neutral wire?

Answer 59

0V

Question 60

Equation for current

Answer 60

I = Q/t

Question 61

State 3 equations for power

Answer 61

P = V x I P = I^2 x R P = E/t