Question

An electric lamp with voltage rating 60W ; 220V is connected to main supply of 110V what current is drawn by lamp from main supply ?​

Answer 1

Answer:

3/22 or 0.136 A

Explanation:

P = 60 W

V = 220 V

Therefore, I = 60/220 = 3/11 or 0.27 A

Now, R = V/I = 220 * 11/3 = 2420/3 Ohm or 806.66 Ohm

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Now,

V = 110 V

Resistance remains the same, ie 2420/3 or 806.66 ohms

So,

I = V/R = 110*3/2420 = 3/22 A or 0.136 A