• Draw a circuit with a 2Ω and a 4 Ω resistor in parallel, running off a 6.0V battery.

• What is the current through the 2 Ω resistor?

• What is the current through the 4 Ω resistor?

• What is the current through the cell?

1)Workbook page 88, Q3.2) Workbook page 89, Q4

Alternating current

L.O.:What is alternating current?What is the frequency of the UK mains supplyHow do we use an oscilloscope to measure the frequency of an alternating current?

Direct current (d.c.)Direct current (d.c.)Direct current (d.c.)Direct current (d.c.)

Direct current (d.c.)

Alternating current (a.c.)Alternating current (a.c.)Alternating current (a.c.)Alternating current (a.c.)

Alternating current

1. An alternating current (a.c.) constantly changes direction. 50Hz means the current changes direction 50 times in one second

2. Mains electricity is an a.c. supply3. A direct current (d.c.) is found in

battery/cell circuits. The current always flows in the same direction

A.C./D.C.A.C./D.C.A.C./D.C.A.C./D.C.

A.C./D.C.

In the UK, the mains frequency is 50 cycles per second (Hz).

A mains circuit has a live wire which is alternately positive and negative every cycle an a neutral wire at zero volts.

1) Workbook page 912) Workbook page 903) Q3, page 884) Q4, page 895) Qs in hand out.