GCSE AQA Physics, 4.2 Electricity.

What is meant by ‘current’. [1 mark]

Flow of electric charge.

Compare the pattern of current flow between series circuit and parallel circuit. [2 marks]

• Same all around in the series circuit.

• Total current seprate through the whole circuit.

Compare the pattern of potential difference between series circuit and parallel circuit. [2 marks]

• Potential difference shared each components in series circuit.

• the potential difference across each components is the same.

Describe the result of graph when current through an ohmic conductor. [2 marks]

Current is directly proportional to the potential difference.

Describe the difference between alternative current and direct current

Direct current is current that flow 1 direction.

Alternative current is current that change direction constantly.

Student has rub a cloth and a plastic rod.

Explain why the friction causes the cloth to become charged. [2 marks]

Transfer of electron from the plastic rod to the cloth.

Scientist uses electrical field lines to explain the force of attraction.

Describe what should the field lines look like when explaining the electrical field of positive charged object. [2 marks]

• Perpendicular to the surface.

• The arrow on the line should be outward.

Scientist uses electrical field lines to explain the force of attraction.

Describe what should the field lines look like when explaining the electrical field of negative charged object. [2 marks]

• Perpendicular to the surface.

• The arrow on the line should be inward.

State each colour of wires in plug in UK. [3 marks]

a) neutral

b) Earth

c) Live

a) Blue.
b) Green and yellow.

c) Brown.

State each functions of wires in plug in UK. [3 marks]

a) neutral

b) Earth

c) Live

a) Complete the circuit.

b) Safety purpose.

c) Carry alternating potential difference.

Power station can need to transport electricity to the homes.

Describe and explain the process of pass electricity to the homes by national grid. [6 marks]

• Electricity pass through step-up transformer.

• To increase potential difference.

• Less energy lost in the power cable.

• Electricity pass through step-down transformer.

• To reduce potential difference to 230 V.

• Safer.

Explain how the resistance of a filament lamp changes as the potential difference across it increases. [3 marks]

• The current increases.

• Causes the temperature of the filament to increase.

• The resistance increases.

Identify what component is it. [1 mark]

LDR

Describe what happen to resistance of LDR when increasing light intensity. [2 marks]

Decreasing.

Identify what component is it. [1 mark]

Thermistor.

Describe what happen to resistance of thermistor when increasing temperature. [2 marks]

Decreasing.