The current flowing through the two bulbs marked as 60 W, 240 V each when connected in series with 240 V source is: |
0.125 A 0.25 A 4 A 2 A |
0.125 A |
The correct answer is Option (1) → 0.125 A The resistance of a bulb is - $R=\frac{V^2}{P}$ where, V (Voltage in circuit) = 240 P (Power of each bulb) = 60 $R=\frac{(240)^2}{60}$ Now, As bulbs are connected in series than total resistance ($R_{total}$) is $R_{total}=R+R$ $=2R$ ∴ I (Current in circuit) = $\frac{240}{2R}$ $=\frac{240×60}{2×240×240}$ $=0.125A$ |