P3

Question 1

Give the definition of static electricity

Answer 1

Static electricity- electric change that has accumulated on an object but is stationary due to the objects inability to conduct

Question 2

Give an example of when static electricity might occur

Answer 2

An example of when static electricity occurs is when two objects that are not good conductors are rubbed together such as a balloon against your hair could rub electrons onto the balloon giving it a negative static electric charge

Question 3

What will objects carrying opposite charges experience?

Answer 3

Objects carrying opposite charges experience a force of attraction

Question 4

What is an electrical field?

Answer 4

An electrical field is a region round a charged object where a force would be exerted on other objects

Question 5

Which way do field line arrows point?

Answer 5

Field line arrows point in the way a nearby positively charged object would be attracted

Question 6

What happens when the electric fields of two charged objects interact?

Answer 6

When the electric fields of two charged objects interact a force is produced.

Question 7

Use the flash cards in the back of phone case to correctly identify all the circuit symbols

Good luck 😊

Answer 7

😊😊

Question 8

Give the definition of resistance

Answer 8

Resistance is the potential difference (energy) needed to drive a current round a circuit

Question 9

Resistance =

Answer 9

Resistance= potential difference/ current

Question 10

What sort of effect does temperature have on resistance and why?

Answer 10

Temperature causes the resistance to increase because it decreased the current because the atoms have more energy and vibrate making it harder for the electrons to pass through

Question 11

Sketch the potential difference current graph of a resistor and describe why it has this shape

Answer 11

A potential difference- current graph of a resistor has a linear shape passing through 0 because potential difference is directly proportional to current at a constant temperature

Question 12

Sketch the potential difference current graph of a filament lamp and describe why it has this shape

Answer 12

The potential difference - current graph of a filament lamp curved because as the current increases it increases the temperature of the lamp which increases the resistance thus either decreasing the current or increasing the potential difference

Question 13

Sketch the potential difference current graph of a diode and describe why it has this shape

Answer 13

A potential difference - current graph of a diode is flat on the left because current will only flow in one direction because of the high resistance in the opposite direction.

Question 14

Name two things you must remember when using an ammeter in a circuit

Answer 14

1) the ammeter must be placed in series with the component

2) the ammeter cannot be parallel to the voltmeter

Question 15

Name one thing you must remember when using a voltmeter in a circuit

Answer 15

1) the voltmeter must be in parallel to the component

Question 16

Explain what a diode is and what it us used for

Answer 16

A diode is a device that only allows current to flow in one direction due to its extremely high resistance in the opposite direction. It is usually made out of a semiconductor such as silicon and used to control currents in circuits such as radio receivers

Question 17

Explain what a light dependant resistor (LDR) is and what it is used for

Answer 17

A light dependant resistor is a component that values its resistance according to the light intensity.
Low light intensity = high resistance
High light intensity= low resistance
This makes LDR’s ideal for automatic outdoor lights because during the day the resistance will drop so the PD will also drop not supplying much energy to the lamp and at night the resistance will raise which will cause the PD to increase supplying more energy

Question 18

Explain what a thermostat is and what they are used for?

Answer 18

A thermostat is a component which varies its resistance depending on the temperature
High temp= low resistance (so less pd is supplied to heater)
Low temp= high resistance(so more pd is supplied to heater)
This makes thermistors ideal for thermostats

Question 19

Give the definition of current and units

Answer 19

Current is the rate of flow of electrons around a circuit

Units- amps

Question 20

Give the definition of charge

Answer 20

Charge is the amount of electrical energy contained in an object, particle or region of space
Unit - coulomb

Question 21

Charge=

Answer 21

Current x time

Question 22

Give the definition and units of potential difference

Answer 22

Potential difference us the difference in electrical potential difference between ten points in a circuit that makes an electric current/ charge move
Units- volts

Question 23

Potential difference =

=

Answer 23

Potential difference=Energy transferred / charge

Potential difference =current x resistance

Question 24

How are current and resistance linked to potential difference

Answer 24

Resistance increases with current because current creates heat which increases resistance. A higher resistance means more energy is needed so the potential difference of battery needs to be greater

Question 25

Give the definition of power

Answer 25

Power is the measure of energy transferred per second through a component

Question 26

Power=
Power=
Power=

Answer 26

Power= energy/ time 
Power= potential difference x current 
Power= current 2 x resistance

Question 27

What is a series circuit?

Answer 27

A series circuit is a circuit with only one branch so the current has only one pathway

Question 28

What is the rule for the current in a series circuit?

Answer 28

The current is the same anywhere in a series circuit

Question 29

What is the rule for the potential difference in a series circuit?

Answer 29

The potential difference is shared between all the components in a series circuit so the pd across the component will add to the pd across the power supply

Question 30

What is the rule for the resistance in a series circuit?

Answer 30

In a series circuit the resistors add up to the total resistance

Question 31

What us the rule for current in a parallel circuit?

Answer 31

The current in a parallel circuit is shared between branches which add up to the current leaving the cell

Question 32

What is the rule for potential difference in parallel circuits?

Answer 32

Potential difference is the same on each branch of a parallel circuit

Question 33

What is the rule for resistance in a parallel circuit

Answer 33

The total resistance of a parallel circuit is less than the resistance of the smallest resistor

Question 34

How can you investigate potential difference in series and parallel circuits?

Answer 34

To investigate potential difference in series and parallel circuits set up a circuit with a power pack, voltmeter and bulb. First ad bulbs in series they should get dimmer as the pd is shared across the branch. Aging bulbs in parallel will not make them get dimmer