Calculate the resistance of a $100 \mathrm{W}$ light bulb that draws a current of $0.43 \mathrm{A}$ from a power supply.

A $12 \mathrm{V}$ car battery can supply a current of $10 \mathrm{A}$ for $5.0$ hours. Calculate how many joules of energy the battery transfers in this time.

A lamp is operated for $20 \mathrm{s}$. The current in the lamp is $10 \mathrm{A}$. In this time, it transfers $400 \mathrm{J}$ of energy to the lamp. Calculate:

(a) How much charge flows through the lamp.

A lamp is operated for $20 \mathrm{s}$. The current in the lamp is $10 \mathrm{A}$. In this time, it transfers $400 \mathrm{J}$ of energy to the lamp. Calculate:

(b) How much energy each coulomb of charge transfers to the lamp

A lamp is operated for $20 \mathrm{s}$. The current in the lamp is $10 \mathrm{A}$. In this time, it transfers $400 \mathrm{J}$ of energy to the lamp. Calculate:

(c) The p.d. across the lamp.

A small immersion heater is connected to a power supply of e.m.f. of $12 \mathrm{V}$ for a time of $150 \mathrm{s}$. The output power of the heater is $100 \mathrm{W}$. What charge passes through the heater?

(A) $1.4\mathrm{C}$

(B) $8.0\mathrm{C}$

(C) $1250\mathrm{C}$

(D) $1800\mathrm{C}$

Which statement defines e.m.f.?

(A) The e.m.f. of a source is the energy transferred when charge is driven through a resistor.

(B) The e.m.f. of a source is the energy transferred when charge is driven round a complete circuit.

(C) The e.m.f. of a source is the energy transferred when unit charge is driven round a complete circuit.

(D) The e.m.f. of a source is the energy transferred when unit charge is driven through a resistor.