Question

$B_1,B_2$ and $B_3$ are three identical bulbs connected as shown in Figure 12.8. When all the three bulbs glow, a current of 3A is recorded by the ammeter A.
What happens to the glow of the other two bulbs when the bulbs $B_1$ gets fused?

Answer 1

Hint: Try to establish relation between Power, Potential difference and Resistance.

Step 1 : Find the power dissipated by each bulb.

Given : Three bulbs connected in parallel to a source of $4.5V$

As all three bulbs are connected in parallel the potential difference across all the three remains same.

Even if any one them is fused rest will still continue to work.

Glow of any bulb depends on the power it consumes

$P=\frac{V^2}{R}$

As the potential difference across each bulb and the resistance of each bulb is constant,

there is no change in the glow even if $B_1$ fuses.