Question 709: Current Electricity

Question

when three identical bulbs of 60 watt, 200 volt rating are connected in series to a 200 volt supply, the power drawn by them will be

Accepted Answer

The resistance of each bulb
$$ = {{{V^2}} \over P} = {{{{\left( {200} ight)}^2}} \over {60}}\Omega $$
When three bulbs are connected in series their resultant resistance
$$ = {{3 	imes {{\left( {200} ight)}^2}} \over {60}}$$
Thus power drawn by bulb when connected across 200 V supply
$$P = {{{V^2}} \over {{R_{re}}}} = {{{{\left( {200} ight)}^2}} \over {3 	imes {{\left( {200} ight)}^2}/60}} = 20W$$

Answer

60 watt

Answer

180 watt

Answer

10 watt

Answer

20 watt

Current Electricity

when three identical bulbs of 60 watt, 200 volt rating are connected in series to a 200 volt supply, the power drawn by them will be

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