A hot plate of an electric oven connected to a 220 V line has two resistance coils A and B, each of 24resistance, which may be used separately, in series or in parallel. What are the currents in the three cases?

__Case (i): When each coil is used separately__

Here, Potential difference, V = 220 V

Resistance of a coil, R = 24

Using Ohm’s Law, the current passing through one coil is given as,

__Case (ii) Calculation of current when the two coils are connected in series__

When the two coils of 24 each are connected in series, then their combined resistance will be R= 24 + 24 = 48

Potential difference, V = 220 V

And, Resistance, R = 48 Q

Again, Current passing through both coils connected in series, is given as:

__Case (iii) Calculation of current when the two coils are connected in parallel__

When the two coils of 24 each are connected in parallel, then their combined resistance will be given as:

Here, Potential difference, V = 220 V

Resistance of two coils in parallel connection, R = 12 (Two coils in parallel)

Now, Current, I =

18