Three bulbs X, Y and Z are connected as shown in figure. The bulbs Y and Z are identical. If bulb Z gets fused, then

Options

A. Both X and Y will glow more brightly
B. Both X and Y will glow less brightly
C. X will glow less brightly and Y will glow more brightly
D. X will glow more brightly and Y will glow less brightly

Answer

C

Explanation

If bulb Z is fused, the current stops flowing through Z. The effective resistance of the circuit due to bulbs X and Y in series becomes more as compared to before. Due to which, the current in the circuit decrease.
`:.` brightness `("current")^(2)` So, the brightness of bulb `xx` decreases, Now, bulb Y gets more current than before fusing the bulb, Z.
`:.` Brightness of bulb will increase