A capacitor of capacitance C has charge Q and stored energy is W. lf the charge is increase to 2Q. The stored energy will be:
Correct answer: D. 4W
- A. W/4
- B. W/2
- C. 2W
- D. 4W
Explanation
We know that the energy stored in a capacitor is given by: W=Q2 /2C Now, if the charge Q increases to 2Q, then the change in energy will be given by: W′=(2Q)2 /2C ⇒4Q2/2C =4W THUS THIS IS THE CORRECT ANSWER.
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Electrostatics describes forces between charges through Coulomb's law, electric fields and field intensity, then uses electric potential to measure energy per unit charge. Capacitors store charge and electrical energy, with capacitance depending on geometry and dielectric material, not simply on the amount of charge present.
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