Question

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

Answer 1

Supply voltage, V = 220 V

Resistance of one coil, R =

(i) Coils are used separately

According to Ohm’s law,

Where,

is the current flowing through the coil

Therefore, 9.16 A current will flow through the coil when used separately.

(ii) Coils are connected in series

Total resistance,

According to Ohm’s law,

Where,

is the current flowing through the series circuit

Therefore, 4.58 A current will flow through the circuit when the coils are connected in series.

(iii) Coils are connected in parallel

Total resistance, is given as

According to Ohm’s law,

Where,

is the current flowing through the circuit

Therefore, 18.33 A current will flow through the circuit when coils are connected in parallel.