Answer:
Will double
Explanation:
The total resistance of a circuit with n resistors in series is equal to the sum of the individual resistances:
[tex]R_T = R_1 + R_2 + ... + R_n[/tex]
In this problem, we have a circuit with initially one light bulb of resistance R, so the total resistance of the circuit is:
[tex]R_T = R[/tex]
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
[tex]R_T = R + R = 2 R[/tex]
So, the resistance has doubled.