Four bulbs B$$_1$$, B$$_2$$, B$$_3$$ and B$$_4$$ of 100 W each are connected to 220 V main as shown in the figure. The reading in the ideal ammeter will be:

Each of the four bulbs ($$B_1, B_2, B_3, B_4$$) is rated at $$100$$ W and connected to a $$220$$ V main. Since they are in parallel across the supply, the current $$I$$ through each individual bulb is $$I = \frac{P}{V} = \frac{100\text{ W}}{220\text{ V}} = \frac{5}{11}\text{ A} \approx 0.454\text{ A}$$

The ammeter measures the combined current required to power all subsequent bulbs in the parallel network: $$B_2$$, $$B_3$$, and $$B_4$$.

$$I_{ammeter} = I_{B2} + I_{B3} + I_{B4}$$

$$I_{ammeter} = 3 \times \left( \frac{5}{11}\text{ A} \right) = \frac{15}{11}\text{ A}$$

$$I_{ammeter} \approx 1.35\text{ A}$$