Which statement about power is correct?

1. The power of a light bulb labelled '12 V, 2 A' is 6 W. If the light bulb is
switched on for 5 hours then 430 kJ of energy are transferred.

2. A powerful appliance transfers less energy per second, so a more powerful
lamp is dimmer than a less powerful one.

3. Potential difference is the power transferred per unit charge, and the current
is the charge that flows per second.

4. The power of a travel kettle labelled '24 V, 5 A' is 120 W. If it heats water for
15 minutes then 108 000 J of energy are transferred.