In the diagram above, three identical lamps each of 100 W are connected in parallel across a potential difference of 250 V. Calculate the reading of the ammeter.
7.5A
2.5A
1.2A
0.8A
O.4A
คำอธิบาย
P = VI ; I = P/V = 100/250 = 0.4A each
Total current 3 x 0.4 = 1.2A
