Question

A current of 1 ampere flows in a series circuit having an electric lamp and a conductor of 5Ω when connected to a 10 V battery. Calculate the resistance of the electric lamp. Now if a resistance of 10Ω is connected in parallel with this series combination, what change (if any) in current flowing through 5Ω conductor and potential difference across the lamp will take place? Give reason.

Answer 1

(ii) Now, a resistance of 10Ω is connected in parallel with the series combination. Therefore, the total resistance of the circuit is given by

Thus, I A current will flow through 10Ω resistor and 1A will flow through the lamp and conductor of 5Ω resistance. Hence, there will be no change in current flowing through 5Ω conductor. Also, there will be no change in potential difference across the lamp.