Charging of Capacitors
Trending Questions
Q. Two capacitors C1=8μF and C2=4μF are connected in series between points A and B. An ideal cell of emf 12V is connected between A and B for a long time. Now, a slab of dielectric constant k=2 is slowly introduced, fully in the gap of capacitor C2.
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/1009164/original_06.png)
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/1009164/original_06.png)
- As the dielectric is introduced, the energy taken from the cell is 192μJ.
- As the dielectric is introduced the increase in electrostatic energy stored in the capacitors is 96μJ.
- The work done by dielectric slab on the filling agent during the filling process is positive.
- The work done by dielectric slab on the filling agent during the filling process is zero.
Q. Find the potential drop across 4 μF capacitor and 6 Ω resistor as shown in the following circuit.
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/917179/original_Q11.png)
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/917179/original_Q11.png)
- 0, 0
- 0 V, 3 V
- 0 V, 2 V
- 2 V, 0 V
Q. Under what conditions current passing through a resistance R can be increased by short-circuiting the battery of emf E2. The internal resistances of the two batteries are r1 and r2 respectively.
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/1250988/original_7Q.png)
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/1250988/original_7Q.png)
- E2r1>E1(R+r2)
- E1r1<E2(R+r1)
- E1r2>E2(R+r1)
- E2r2<E1(R+r2)
Q. A leaky parallel plate capacitor is filled completely with a material having dielectric constant K=5 and electric conductivity σ=7.4×10–12Ω–1m–1. If the charge on the plate at the instant t=0 is q=8.85μC, then the leakage current at the instant t=12 sec is approximately x×10–1μA where x is
(round off to nearest integer)
(round off to nearest integer)
Q. If a capacitor of 10μF is charged to 10V and then connected to a new circuit to discharge through a10Ω resistor, the charge on it after 20μs is .
- 72μC
- 82μC
- 62μC
- 52μC
Q. Two circular loops of radii 0.05 m and 0.09 m are arranged such that their axes coincide and their centres are 0.12 m apart. Charge of 10−6 C is spread uniformly on each loop. The potential difference between the centres of the loops is
- 71 kV
- 64 kV
- 95 kV
- 82 kV
Q. An air capacitor of capacity 10 μF is connected to a battery of 12 V. Now the space between the plates is filled with a liquid of dielectric constant 5. The additional charge that flows to the capacitor is
- 600 μC
- 120 μC
- 24 μC
- 480 μC
Q. The voltage across a parallel plate capacitor of capacitance 127 μF is increased from 3.887 V to 4.887 V. The extra charge that flows through the battery is
- 127 μC
- 254 μC
- 63.5 μC
- 508 μC
Q. At t=0 , switch S1 is closed and remains closed for a long time and S2 remains open. Now S1 is opened and S2 is closed. Find out the charge on the capacitor long after that moment.
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/1230853/original_10.qstn.png)
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/1230853/original_10.qstn.png)
Q. Capacitors only allow a current to flow (Choose all correct options)
- When charging
- When discharging
- At all times
- When not connected to a circuit.