Now, let us derive the expression of energy stored in the capacitor. For that, let at any stage of charging, the electric charge stored in the capacitor is q coulombs and the voltage the plates of the capacitor is v volts. Then, q ∝ v ⇒ q = Cv
Calculate the change in the energy stored in a capacitor of capacitance 1500 μF when the potential difference across the capacitor changes from 10 V to 30 V. Step 1: Write down the equation for energy stored in terms of capacitance C and p.d V Step 2: The change in energy stored is proportional to the change in p.d Step 3: Substitute in values
The energy stored in a capacitor is nothing but the electric potential energy and is related to the voltage and charge on the capacitor. If the capacitance of a conductor is C, then it is initially uncharged and it acquires a potential difference V when connected to a battery. If q is the charge on the plate at that time, then
In this condition, the capacitor is said to be charged and stores a finite amount of energy. Now, let us derive the expression of energy stored in the capacitor. For that, let at any stage of charging, the electric charge stored in the capacitor is q coulombs and the voltage the plates of the capacitor is v volts.
From the expression of stored energy in a capacitor, it is clear that the energy stored is directly proportional to capacitance of the capacitor, which means a capacitor of higher capacitance can store more amount of energy for the same voltage and vice-versa.
Energy stored in a capacitor is electrical potential energy, and it is thus related to the charge Q Q and voltage V V on the capacitor. We must be careful when applying the equation for electrical potential energy ΔPE = qΔV Δ P E = q Δ V to a capacitor. Remember that ΔPE Δ P E is the potential energy of a charge q q going through a voltage ΔV Δ V.