10.30 Explain how the power transfer in any circuit device is related to the 28 23 30, 161 potential difference across it and the current in it 10.31 Recall and use the equations: 35 30 37, 168 electrical power (watt, W) = current (ampere, A) × potential difference (volt, V) electrical power (watt, W) = current squared (ampere2 , A2) × resistance (ohm, Ω) 10.32 Describe how, in different domestic devices, energy is transferred 35-7 30-1 37-9, 168-9 from batteries and the a.c. mains to the energy of motors and heating devices 10.33 Explain the difference between direct and alternating voltage 35-7 30-1 37-9, 168-9 10.34 Describe direct current (d.c.) as movement of charge in one direction 35-7 30-1 37-9, 168-9 only and recall that cells and batteries supply direct current (d.c.) 10.35 Describe that in alternating current (a.c.) the movement of charge 35-7 30-1 37-9, 168-9 changes direction 10.36 Recall that in the UK the domestic supply is a.c., at a frequency of 50 35-7 30-1 37-9, 168-9 Hz and a voltage of about 230 V 10.37 Explain the difference in function between the live and the neutral 34 29 36, 167 input wires 10.38 Explain the function of an earth wire and of fuses or circuit breakers 34 29 36, 167 in ensuring safety 10.39 Explain why switches and fuses should be connected in the live wire 25-6 20 27-8, 158 of a domestic circuit 10.40 Recall the potential differences between the live, neutral and 34 29 36, mains wires 10.41 Explain the dangers of providing any connection between the live 34 29 167 wire and earth 10.42 Describe, with examples, the relationship between the power ratings 35 31 37, 169 for domestic electrical appliances and the changes in stored energy when they are in use Topic 11 Static electricity –
10.30 Explain how the power transfer in any circuit device is related to the potential difference across it and the current in it 28 23 30, 161 10.31 Recall and use the equations: electrical power (watt, W) = current (ampere, A) × potential difference (volt, V) electrical power (watt, W) = current squared (ampere2 , A2) × resistance (ohm, Ω) 35 30 37, 168 10.32 Describe how, in different domestic devices, energy is transferred from batteries and the a.c. mains to the energy of motors and heating devices 35-7 30-1 37-9, 168-9 10.33 Explain the difference between direct and alternating voltage 35-7 30-1 37-9, 168-9 10.34 Describe direct current (d.c.) as movement of charge in one direction only and recall that cells and batteries supply direct current (d.c.) 35-7 30-1 37-9, 168-9 10.35 Describe that in alternating current (a.c.) the movement of charge changes direction 35-7 30-1 37-9, 168-9 10.36 Recall that in the UK the domestic supply is a.c., at a frequency of 50 Hz and a voltage of about 230 V 35-7 30-1 37-9, 168-9 10.37 Explain the difference in function between the live and the neutral input wires 34 29 36, 167 10.38 Explain the function of an earth wire and of fuses or circuit breakers in ensuring safety 34 29 36, 167 10.39 Explain why switches and fuses should be connected in the live wire of a domestic circuit 25-6 20 27-8, 158 10.40 Recall the potential differences between the live, neutral and mains wires 34 29 36, 10.41 Explain the dangers of providing any connection between the live wire and earth 34 29 167 10.42 Describe, with examples, the relationship between the power ratings for domestic electrical appliances and the changes in stored energy when they are in use 35 31 37, 169 Topic 11 – Static electricity