Current Electricity

A bulb is made using two filaments.

A switch selects whether the filaments are used individually or in parallel.

When used with a 15 V battery, the bulb can be operated at 5 W, 10 W or 15 W.

What should be the resistances of the filaments?

1 Answers

1161

Akash Anand ·2014-06-07 04:42:32

using V²/R=Power for all the three cases, you will get the result.
The answer should be 15 ohm.

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