Question

When a second identical bulb is added in series to a circuit with a single bulb, the resistance of the circuit

Answer 1

Will double

Step-by-step explanation:

The total resistance of a circuit with n resistors in series is equal to the sum of the individual resistances:

`R_T = R_1 + R_2 + ... + R_n`

In this problem, we have a circuit with initially one light bulb of resistance R, so the total resistance of the circuit is:

`R_T = R`

Later, a second identical bulb (so, same resistance R) is added in series to the circuit; so applying the previous formula, we see that the new total resistance is

`R_T = R + R = 2 R`

So, the resistance has doubled.