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Standard XII

Physics

EMF and EMF Devices

The switch sh...

Question

The switch shown in the figure is closed at $t = 0$ . The charge on the capacitor as a function of time is given by

C V (1 - e^{- t / R C})

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3 C V (1 - e^{- t / R C})

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C V (1 - e^{- 3 t / R C})

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C V (1 - e^{- t / 3 R C})

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Solution

The correct option is C $C V (1 - e^{- 3 t / R C})$
The net resistance of the circuit is $R_{e q} = (1 / R + 1 / R + 1 / R)^{- 1} = R / 3$
The charge on capacitor at time t is $q (t) = q_{0} (1 - e^{- t / C R_{e q}}) = C V (1 - e^{- 3 t / C R})$

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Two capacitors of capacitance 2C and C are charged to potential difference 2V and V respectively. Now the charged capacitors are connected with a resistor R as shown in figure. Switch ‘S’ is closed at t = 0.

What is the current in circuit as function of time?

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The switch shown in the figure is closed at t=0. The charge on the capacitor as a function of time is given by

The correct option is C CV(1−e−3t/RC)The net resistance of the circuit is Req=(1/R+1/R+1/R)−1=R/3The charge on capacitor at time t is q(t)=q0(1−e−t/CReq)=CV(1−e−3t/CR)

The switch shown in the figure is closed at $t = 0$ . The charge on the capacitor as a function of time is given by

The correct option is C $C V (1 - e^{- 3 t / R C})$
The net resistance of the circuit is $R_{e q} = (1 / R + 1 / R + 1 / R)^{- 1} = R / 3$
The charge on capacitor at time t is $q (t) = q_{0} (1 - e^{- t / C R_{e q}}) = C V (1 - e^{- 3 t / C R})$