Electricity

The nucleus of an atom contains

• Only electrons

• Only neutrons

• Electrons and neutrons

• Protons and neutrons

A battery sends a current through a metal wire.

Direct current is movement of charge

• backwards and forwards

• in many directions

• in one direction

• up and down

A metal wire carries an electric current. The charge that flows in the wire is made up of

• electrons

• protons

• positive ions

• negative ions

The graphs show how the current in a component changes with the voltage applied across the component.

Which graph matches the component

• 
• 
• 

The graphs show how the current in a component changes with the voltage applied across the component.

Which graph matches the component

• 
• 
• 

The graphs show how the current in a component changes with the voltage applied across the component.

Which graph matches the component

• 
• 
• 

A student investigates resistors connected in series in an electrical circuit.

The student has:         

a 3.0 V battery        

a 22 Ω resistor         

a resistor marked X.The student does not know the value of the resistor marked X.

The student decides to measure the potential difference (voltage) across resistor X.

Figure 15 shows the circuit that the student connected.

The circuit is connected incorrectly. Describe how the student should correct the mistake.

Answer explanation

Voltmeter is in series.

Needs to be in parallel with resistor X

A wier in a circuit carries a current of 0.9A. Calculate the quantity of charge that flows through the wire in 50s. State the unit of charge with your answer.

Charge = current x time

Answer explanation

Q = It

= 0.9 x 50

= 45 C (Coulombs)

A student sets up an experiment to measure the potential difference (voltage) across a filament lamp.

She changes the current through the lamp.

The diagram shows the circuit she used.

Calculate the resistance of the lamp when the current is 0.44 A and the potential difference is 10.0 V

R = V/I

Answer explanation

R = V/I

= 10 / 0.44

= 23 ohms

Draw a circuit diagram you could use to investigate the relationship between potential difference, current and resistance for a filament lamp.

Answer explanation