0
You visited us 0 times! Enjoying our articles? Unlock Full Access!
Question

A 900 pF capacitor is charged by 100 V battery as shown in figure. The capacitor is disconnected from the battery and connected to another 900 pF capacitor. What is the electrostatic energy stored by the system?
112116_fd8748d1ce5d461b93adc47c55c794b2.png
  1. 1.25×106J
  2. 5.25×106J
  3. 2.25×106J
  4. 8.24×106J

A
1.25×106J
B
5.25×106J
C
2.25×106J
D
8.24×106J
Solution
Verified by Toppr

Step 1: Initial energy stored in the capacitor(Ui)
Ui=12C1V2=12×900×1012F×(100)2 =4.5×106J

Step 2: Charge on each capacitor
C1=900 pF is connected with another C2=900 pF capacitor.
In steady-state, the two capacitors will have the same potential, say V. Let say Q1 and Q2 are the charges on the capacitor.
Q1900 pF=Q2900 pFQ1=Q2

Initial charge =Q
Charge conservation : Q1+Q2=Q
Q1=Q2, Q2=Q2

Step 3: New potential on the capacitors.
V=Q1C1=Q2C1=V2=1002=50V.

Step 4: Final electrostatic energy stored
Uf=12C1V2+12C2V2 [C1=C2]
=C1V2
=900×1012 F×(50)2=2.25×106J
Hence, Option (C) is correct.

Note: UiUf=2.25×106J
This much energy is lost in the form of heat.

2110275_112116_ans_9ad848b584b14d06a2e698b8d6c1058b.png

Was this answer helpful?
57
Similar Questions
Q1
A 900 pF capacitor is charged by 100 V battery as shown in figure. The capacitor is disconnected from the battery and connected to another 900 pF capacitor. What is the electrostatic energy stored by the system?
112116_fd8748d1ce5d461b93adc47c55c794b2.png
View Solution
Q2
A capacitor of capacitor of capacitance 700 pF is charged by 100 V battery. The electrostatic energy stored by the capacitor is:
View Solution
Q3
A 600pF capacitor is charged by a 200V supply. It is then disconnected from the supply and is connected to another uncharged 600 pF capacitor. How much electrostatic energy is lost in the process? (1 pF = 1012 F)
View Solution
Q4
A 12pF capacitor is connected to a 50V battery. How much electrostatic energy is stored in the capacitor?
View Solution