Potential difference and power — practice questions

1. To find the power (P), we use the formula $P = VI$: Given: $V = 12 \text{ V}$, $I = 0.5 \text{ A}$ $P = 12 \text{ V} \times 0.5 \text{ A} = 6 \text{ W}$ The electrical power dissipated by the bulb is 6 Watts.
2. To find the total energy (E), we use the formula $E = VIt$. First, convert the time to seconds: $t = 10 \text{ minutes} \times 60 \text{ seconds/minute} = 600 \text{ s}$ Now, substitute the values into the energy formula: $E = 12 \text{ V} \times 0.5 \text{ A} \times 600 \text{ s}$ $E = 6 \text{ W} \times 600 \text{ s} = 3600 \text{ J}$ The total electrical energy converted by the bulb is 3600 Joules.

$V = IR = 2.5 \times 8.0 = 20\,\text{V}$ $P = I^2R = (2.5)^2 \times 8.0 = 50\,\text{W}$