Advertisements
Advertisements
प्रश्न
Each capacitor in figure has a capacitance of 10 µF. The emf of the battery is 100 V. Find the energy stored in each of the four capacitors.

Advertisements
उत्तर
Capacitors b and c are in parallel; their equivalent capacitance is 20 µF.
Thus, the net capacitance of the circuit is given by
`1/C_"net" = 1/10 + 1/20 + 1/10`
`⇒ 1/C_"net" = (2+1+2)/20 = 5/20`
`⇒ C_"net" = 4 "uF"`
The total charge of the battery is given by
`Q = C_"net"V = (4 "uF") xx (100 "V") = 4 xx 10^-4 C`
For a and d,
`q = 4 xx 10^-4 "C" and "C" = 10^-5 "F"`
`therefore E = q^2/(2C) = (4 xx 10^-4)/(2 xx 10^-5)`
`⇒ E = 8 xx 10^-3 "J" = 8 "mJ"`
For b and c,
`q = 4 xx 10^-4 "C" and "C"_(eq) = 2"C" = 2 xx 10^-5 "F"`
`therefore V = q/C_(eq) (4 xx 10^-4)/(2 xx 10^-5) = 20 V`
`⇒ E = 1/2 CV^2`
`⇒ E = 1/2 xx 10^-5 xx 400`
`⇒ E = 2 xx 10^-3 "J" = 2 "mJ"`
APPEARS IN
संबंधित प्रश्न
A 12 pF capacitor is connected to a 50 V battery. How much electrostatic energy is stored in the capacitor?
Find the charge on the capacitor as shown in the circuit.

(a) Find the current in the 20 Ω resistor shown in the figure. (b) If a capacitor of capacitance 4 μF is joined between the points A and B, what would be the electrostatic energy stored in it in steady state?

A 20 μF capacitor is joined to a battery of emf 6.0 V through a resistance of 100 Ω. Find the charge on the capacitor 2.0 ms after the connections are made.
How many time constants will elapse before the current in a charging RC circuit drops to half of its initial value? Answer the same question for a discharging RC circuit.
A capacitor of capacitance 12.0 μF is connected to a battery of emf 6.00 V and internal resistance 1.00 Ω through resistanceless leads. 12.0 μs after the connections are made, what will be (a) the current in the circuit (b) the power delivered by the battery (c) the power dissipated in heat and (d) the rate at which the energy stored in the capacitor is increasing?
By evaluating ∫i2Rdt, show that when a capacitor is charged by connecting it to a battery through a resistor, the energy dissipated as heat equals the energy stored in the capacitor.
A point charge Q is placed at the origin. Find the electrostatic energy stored outside the sphere of radius R centred at the origin.
A large conducting plane has a surface charge density `1.0 xx 10^-4 "Cm"^-2` . Find the electrostatic energy stored in a cubical volume of edge 1⋅0 cm in front of the plane.
Obtain the expression for the energy stored in a capacitor connected across a dc battery.
A capacitor is a device that stores ____________.
If the p. d. across a capacitor is increased from 10 V to 30 V, then the energy stored with the capacitor ____________.
A 2µF capacitor is charge to 100 volt and then its plate are connected by a conducting wire. The heat produced is:-
A parallel plate capacitor has a uniform electric field `overset(->)("E")` in the space between the plates. If the distance between the plates is ‘d’ and the area of each plate is ‘A’, the energy stored in the capacitor is ______
(ε0 = permittivity of free space)
Do free electrons travel to region of higher potential or lower potential?
Which expression gives the work done in transferring charge \(q\) through potential difference \(V\) in a capacitor?
Evaluating the work integral for charging a capacitor from \(0\) to \(Q\) gives which result?
