Edexcel iGCSE Electric Circuits

1. The heating element of a kettle has a potential difference of 230V. If 138kJ of energy is transferred to boil some water, calculate the total amount of charge that flows through the kettle.

Answer __________ (give value without unit)

1b. Give the unit for the numerical answer to Q1.

2. What is the correct relationship between current, charge and time

3. Calculate the current through a resistor when a charge of 630C flows in 3 minutes.

Answer = ___ A

4. The direction of flow of positive charge from the positive terminal of a cell to the negative terminal is called ___________ current.

Draw a circuit diagram to show how you would obtain an IV characteristic for a bulb.

Answer explanation

- Cell and bulb in series

- Variable resistor in series to vary the current

- Ammeter in series to measure current

- Voltmeter parallel to bulb to measure p.d.

- switch is optional!

This is the current characteristic graph for which component.

• Filament lamp

• Non-ohmic resistor

• Diode

• Ohmic resistor

Answer explanation

Ohmic means "obeys Ohm's law" which states that current must be proportional to voltage.

This means the graph must always be a straight line.

Ohmic resistors have a constant value of resistance as long as their _______ remains constant.

Explain the shape of this IV characteristic and state which component it belongs to.

Which equation correctly describes the relationship between resistance, current and voltage.