Answer:
The new energy is 1/16 of the original energy
Explanation:
A capacitor is an electric device which is able to store charge when it is connected to a power supply.
The energy stored in a capacitor is given by the equation
where:
Q is the charge stored on the capacitor
C is the capacitance of the capacitor
For the capacitor in this problem, initially we have
E = 7 J (energy) when the charge stored is Q and the capacitance is C
Later, the charge is decreased to 1/4 of its original value, so the new charge is
Since the capacitance remains the same, the new energy is
Therefore, the new energy is 1/16 of the original energy.