Answer:
(a) The energy stored in the capacitor quadruples its original value.
Explanation:
Consider C be the capacitance of the parallel plate capacitor and V be the voltage applied across the parallel plate capacitors.
Thus, the original energy stored in the capacitor is determine by the relation:
[tex]E_{1}=\frac{1}{2} CV^{2}[/tex] ...(1)
Now, the voltage across the parallel plate capacitors becomes double while the capacitance remains same, that is,
New voltage = 2V
New Capacitance = C
Thus, the new energy stored in the capacitor is:
[tex]E_{2}=\frac{1}{2} C(2V)^{2}[/tex]
[tex]E_{2}=4\frac{1}{2} CV^{2}[/tex]
Substitute equation (1) in the above equation.
[tex]E_{2}=4E_{1}[/tex]