Question
Forty electric bulbs are connected in series across a $$220\,V$$ supply. After one bulb is fused the remaining $$39$$ are connected again in series across the same supply. The illumination will be
A.
more with $$40$$ bulbs than with $$39$$
B.
more with $$39$$ bulbs than with $$40$$
C.
equal in both the cases
D.
in the ratio $${40^2}:{39^2}$$
Answer :
more with $$39$$ bulbs than with $$40$$
Solution :
Since, the voltage is same for the two combinations, therefore $$H \propto \frac{1}{R}.$$ Hence, the combination of $$39$$ bulbs will glow more.