Question

Three bulbs $A,B$ and $C$ are connected as shown in figure. The bulbs $B$ and $C$ are identical. If the bulb $C$ is fused, then:

• A. Brightness of both bulbs $A$ and $B$ will increase
• B. Brightness of both bulbs $A$ and $B$ will decrease
• C. Brightness of the bulb $A$ decrease and that of bulb $B$ increases
• D. None of the bulbs will glow

Answer 1

The correct option is C Brightness of the bulb $A$ decrease and that of bulb $B$ increases

In circuit, bulbs $B$ and $C$ are parallel with each other and bulb $A$ is in series with this combination. If bulb $C$ is fused then bulb $A$ will glow less brightly because current flowing is decreased but bulb $B$ will glow a bit more brightly as the voltage is increased.