Use the following information to answer the next question.

A ceiling fan of 40 W is connected in parallel connection with a fluorescent light bulb of 30 W. They both are connected to a supply voltage of 220 V.

The equivalent resistance of the given combination is

Options
  • A)

    132.8 Ω

  • B)

    341.2 Ω

  • C)

    691.4 Ω

  • D)

    724.6 Ω

Relation between power , voltage and resistanceP =v2RfanRfan = 220×22040 = 1210 ohmbulbRbulb = 220×22030 = 1613.3 ohmAs they are connected in parallel equivalent resistance is R1R = 1Rfan + 1RbulbR = Rfan ×RbulbRfan + Rbulb = 1210×1613.31210+1613.3 = 691.42 ohm

Hence option (c) is correct.

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