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JEE Main201911 Jan 2019Morning ShiftPhysicsCurrent ElectricityActual

Two equal resistances when connected in series to a battery, consume electric power of 60 ~W . If these resistance are now connected in parallel combination to the same battery, the electric power consumed will be :

Options

  1. A60 ~W
  2. B240 ~W
  3. C120 ~W
  4. D30 ~W

Correct answer

B. 240 ~W

Step-by-step solution

When two resistances are connected in series, R_ e q =2 R Power consumed, P = ² R _ ea = ² 2 R In parallel condition, R _ eq = R / 2 New power, P ^ = ² ( R / 2) or P ^ =4 P =240 ~W ( P =60 ~W )

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