Four bulbs B₁, B₂, B₃ and B₄ of 100 W each are connected to 220 V main as shown in the figure. The reading in an ideal ammeter (as shown) will be [Figure: two horizontal rails fed by the 220 V main at the left end; bulbs B₁, B₂, B₃, B₄ are in four vertical branches between the rails, in order from…

Question

Four bulbs B₁, B₂, B₃ and B₄ of 100 W each are connected to 220 V main as shown in the figure. The reading in an ideal ammeter (as shown) will be [Figure: two horizontal rails fed by the 220 V main at the left end; bulbs B₁, B₂, B₃, B₄ are in four vertical branches between the rails, in order from left to right; the ammeter sits in the bottom rail between the B₁ branch and the B₂ branch, so it carries the current of B₂, B₃ and B₄.]

Accepted Answer

(3) 1.35 A. Each bulb gets the full 220 V: I=P/V=(100)/(220)=0.4545 A. The ammeter lies in the rail beyond the B₁ branch, so it carries the current of B₂, B₃ and B₄. I_A=3×0.4545≈1.36 A, which matches 1.35 A.

Step-by-step solution

Why the other options are wrong