In the following circuit the switch S is closed at t   = 0 . The charge on the capacitor C 1 as a…

In the following circuit the switch Sis closed at t =0. The charge on the capacitor C1 as a function of time will be given by Ceq= C1C2C1+ C2

  1. C1E 1-exp-tRC1
  2. CeqE exp-tRCeq
  3. CeqE 1-exp-tRCeq
  4. C2E 1-exp-tRC2

Solution

In given circuit capacitors C1 and C2 are connected in series , so equivalent capacitance will be 

1Ceq=1C1 +1C2 Ceq=C1C2C1+C2 

at t = 0, the switch is closed and capacitors start charged, at time t 

charge on the capacitor is given by 

q= q0 1-e-t/τ

where q0 is the maximum charge on the capacitor at steady state and τ is the time constant.

and q0 =CeqE and τ = RCeq

Then from the above equation

q= CeqE 1-e-t/RCeq

q= CeqE 1-exptRCeq
Both capacitor will have same charge as they are connected in series

Asked in: JEE Main 2018 (16 Apr Online)

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