JEE MainPhysicsCapacitorMCQ+4 / −1
If the charge on a capacitor is increased by 2 C, the energy stored in it increases by 44%. The original charge on the capacitor is (in C)
- A10
- B20
- C30
- D40
View written solutionFree
Correct answer: A
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Use the energy formula for a capacitor
For a capacitor of fixed capacitance , the energy stored is
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Let the original charge be
After increasing the charge by , the new charge becomes
So the new energy is
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Use the given percentage increase in energy
The energy increases by , so
Therefore,
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Simplify
Cancel from both sides:
Taking square root:
since charge is positive.
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Solve for
-
Check with options
The original charge is
So the correct option is A.
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