Electric Field
Electric Circuit

An electric circuit is the path through which electric current flows.

An electric circuit consists of an energy source (battery) connected through connecting wires(conductor) to a load (e.g electric bulb) and a key or switch. The key serves to open or close the circuit.

Types of electric circuit

  1. Open circuit:

    This is a circuit with a gap or opening in the conducting path. The current flow to the external load or resistor is interrupted hence there is no current flow to the external load.

  2. Closed circuit:

    In this circuit, there is no interruption or gap in the conducting path. Current flows freely to the external load or resistor.

  3. Short circuit:

    This is a closed circuit connected to no external load.

Potential difference

Potential difference is the work done to move a unit charge from one point to another in an electric field . It is measured in volts (V).

$$ V = \frac{W}{Q}$$

Where;

V = potential difference in Volts (V)

Q = Quantity of electricity in Coulumb (C)

W = workdone in joules (J)

Calculations

Example 1: A 50\( \mu \)C charge flows through a conductor. If the potential difference between its ends is 40mV, find the work done by the charge(JAMB)

Solution

$$ V = \frac{w}{Q} $$ $$ w = QV $$ $$ Q = 50 \mu C= 5 × 10^{-5} C$$ $$ V = 40mV = 0.04V $$ $$ Q = 5 × 10^{-5} × 0.04 = 2 × 10^{-6}J $$

Potential difference and workdone calculator




Formulas:
  1. For 1: $$ W = Q \times v $$
  2. For 2: $$ v = \frac{W}{q} $$
  3. For 3: $$ Q = \frac{W}{v} $$
Select the formula to use the calculator. Input the values for the parameters to solve using the calculator. Use the information below as a guide.

Summary