Advertisements
Advertisements
Question

The figure shows a network of five capacitors connected to a 100 V supply. Calculate the total energy stored in the network.
Advertisements
Solution

As the both 3 uF capacitors are connected in parallel, so net capacitance between branch EH = 3 + 3 = 6μF
Similarly, the capacitance 2 uF and 1uF at corner B are also connected in parallel, so the net capacitance of branch FG = 2 + 1 = 3 μF
If reconstruct the given figure according to the above calculations, we can see that 6 μF capacitors and 3 μF capacitors are connected in series and another 2 μF capacitor is connected in parallel with both of them.

Hence net capacitance Between D and C `= 2 + (3xx6)/(3+6) = 2+2 = 4 mu"F"`
The total capacitance of the circuit, Cnet = 4μF
Total voltage applied, V = 100V
Energy stored in the network `= 1/2 "C"_"net""V"^2 = 1/2 xx 4xx10^-6 xx (100)^2 = 0.02 "J"`
APPEARS IN
RELATED QUESTIONS
A capacitor 'C', a variable resistor 'R' and a bulb 'B' are connected in series to the ac mains in circuit as shown. The bulb glows with some brightness. How will the glow of the bulb change if (i) a dielectric slab is introduced between the plates of the capacitor, keeping resistance R to be the same; (ii) the resistance R is increased keeping the same capacitance?

An electrical technician requires a capacitance of 2 µF in a circuit across a potential difference of 1 kV. A large number of 1 µF capacitors are available to him each of which can withstand a potential difference of not more than 400 V. Suggest a possible arrangement that requires the minimum number of capacitors.
Figure 4 below shows a capacitor C, an inductor L and a resistor R, connected in series
to an a.c. supply of 220 V

Calculate:
1) The resonant frequency of the given CLR circuit.
2) Current flowing through·the circuit.
3) Average power consumed by the circuit.
A circuit is set up by connecting inductance L = 100 mH, resistor R = 100 Ω and a capacitor of reactance 200 Ω in series. An alternating emf of \[150\sqrt{2}\] V, 500/π Hz is applies across this series combination. Calculate the power dissipated in the resistor.
If the capacitors in the previous question are joined in parallel, the capacitance and the breakdown voltage of the combination will be
A parallel-plate capacitor is connected to a battery. A metal sheet of negligible thickness is placed between the plates. The sheet remains parallel to the plates of the capacitor.
A parallel-plate capacitor having plate area 25 cm2 and separation 1⋅00 mm is connected to a battery of 6⋅0 V. Calculate the charge flown through the battery. How much work has been done by the battery during the process?
A wire of resistance ‘R’ is cut into ‘n’ equal parts. These parts are then connected in parallel with each other. The equivalent resistance of the combination is:
An ac circuit consists of a series combination of circuit elements X and Y. The current is ahead of the voltage in phase by `pi/4`. If element X is a pure resistor of 100 Ω,
(a) name the circuit element Y.
(b) calculate the rms value of current, if rms of voltage is 141 V.
(c) what will happen if the ac source is replaced by a dc source
The equivalent capacitance of the combination shown is:

