Energy and Voltage in Circuits

Which statement correctly describes what happens to the current in a series circuit when the resistance is increased?

A circuit contains a battery and two resistors, R1 and R2, connected in series. R1 = 4 Ω and R2 = 8 Ω. The battery supplies a voltage of 12 V.

State two advantages of using parallel circuits instead of series circuits for wiring lights in a house.

A current of 0.8 A flows through a wire for 30 seconds. Calculate the total charge that passes through the wire. Include units in your answer.

The table below shows the results of an experiment to investigate the current through a wire as the voltage is increased.

a) Plot a graph of current (y-axis) against voltage (x-axis), and draw the best fit straight line.

b) Use your graph to state the relationship between current and voltage for a wire at constant temperature.

Explain, with reasons, why LDRs are often used in automatic lighting systems. State how their resistance changes with light intensity.

Describe an experiment you could do to find the relationship between current and voltage for a resistor. Your answer should include:

- A description or diagram of the circuit you would use - How you would take your measurements - What you would record - How you would use the data to determine the relationship

A heater is connected to a 230 V supply and draws a current of 4.0 A for 5 minutes. Calculate the total energy transferred by the heater in this time. Include units in your answer.