Advertisements
Advertisements
Question
Three circuits, each consisting of a switch 'S' and two capacitors, are initially charged, as shown in the figure. After the switch has been closed, in which circuit will the charge on the left-hand capacitor
(i) increase,
(ii) decrease, and
(iii) remains the same? Give reasons.
Advertisements
Solution
When charged capacitors are connected to each other then the charge will flow from the capacitor with higher potential towards the capacitor with lower potential until a common potential is reached.
(a) In fig. (a) the potential of both the capacitor is same so the charge on left hand capacitor remains the same.
(b) In fig. (b) the potential of left hand capacitor is high so charge from 6Q to 3Q. Therefore charge on left hand capacitor will decrease. (c) In fig.
(c) the potential of left hand capacitor is low so charge will flow from 3Q to 6Q. Therefore charge on the left-hand capacitor will increase.
APPEARS IN
RELATED QUESTIONS
Find the equivalent capacitance of the network shown in the figure, when each capacitor is of 1 μF. When the ends X and Y are connected to a 6 V battery, find out (i) the charge and (ii) the energy stored in the network.
Two identical capacitors of 12 pF each are connected in series across a battery of 50 V. How much electrostatic energy is stored in the combination? If these were connected in parallel across the same battery, how much energy will be stored in the combination now?
Also find the charge drawn from the battery in each case.
A capacitor has capacitance C. Is this information sufficient to know what maximum charge the capacitor can contain? If yes, what is this charges? If no, what other information is needed?
Three capacitors of capacitances 6 µF each are available. The minimum and maximum capacitances, which may be obtained are
It is required to construct a 10 µF capacitor which can be connected across a 200 V battery. Capacitors of capacitance 10 µF are available but they can withstand only 50 V. Design a combination which can yield the desired result.
Find the capacitance of the combination shown in figure between A and B.
A capacitor of capacitance 10 μF is connected to a battery of emf 2 V. It is found that it takes 50 ms for the charge of the capacitor to become 12.6 μC. Find the resistance of the circuit.
A parallel-plate capacitor of capacitance 5 µF is connected to a battery of emf 6 V. The separation between the plates is 2 mm. (a) Find the charge on the positive plate. (b) Find the electric field between the plates. (c) A dielectric slab of thickness 1 mm and dielectric constant 5 is inserted into the gap to occupy the lower half of it. Find the capacitance of the new combination. (d) How much charge has flown through the battery after the slab is inserted?
The variation of inductive reactance (XL) of an inductor with the frequency (f) of the ac source of 100 V and variable frequency is shown in fig.
- Calculate the self-inductance of the inductor.
- When this inductor is used in series with a capacitor of unknown value and a resistor of 10 Ω at 300 s–1, maximum power dissipation occurs in the circuit. Calculate the capacitance of the capacitor.
The positive terminal of 12 V battery is connected to the ground. Then the negative terminal will be at ______.
