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NTA Abhyas JEE Main2020PhysicsCurrent ElectricityPractice

A circuit consists of three identical lamps connected to a battery as shown in the figure. When the switch S is closed then the intensities of lamps A and B

Options

  1. Awill increase by eight times
  2. Bwill decrease by two times
  3. Cwill increase by more than two times
  4. Dwill remain the same

Correct answer

C. will increase by more than two times

Step-by-step solution

After closing of S C bulb or lamp become short circuited potential across A and B before closing of S = V 3 Potential across A and B after closing of S = V 2 As P ∝ V 2 ∴ P i P f = 4 9 P f = P i × 9 4 = 2.25 P i

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