Electrical Energy

Electrical Energy

1. From the definition of potential difference, the electrical work done is given by the equation $$W=QV$$ Where
   W = work
   Q = charge
   V = potential difference
   

2. Since the work done must be equal to the energy to do the work, therefore we can also say that, the electrical energy ( E ) is also given by the formula $$E=QV$$

Example
Given that the potential difference across a bulb is 240V and the current that flow through the bulb is 0.25A. Find the energy dissipated in the bulb in 30s.

Answer:
Formula of current,
$$I=\frac{Q}{t}$$ hence
$$Q=It$$
Energy dissipated,
$$\begin{array}{l}E=QV\\ E=(It)V\\ E=(0.25)(30)(240)\\ E=1800J\end{array}$$