Question

How to calculate potential difference

Answer 1

Firstly, I would like to make sure that you know what potential difference is. Some students get confused when they see the two words potential difference. This is a silly mistake as it can be translated to VOLTAGE (refers to the same thing).

To calculate voltage, there are two formulas at secondary level:

1) P(power /watts) = I(current /amperes) * V (voltage /volts)

  In this case, knowing the power and the current, you can make the V subject of the formula (P/I = V) and find the voltage in the circuit. This formula is usually in relation to an appliance.

2) V(voltage /volts) = I(current/ amperes) * R(resistance /ohms)

   Knowing the current and the resistance in your circuit leads to the discovery of the voltage in the circuit. If there is a resistor in your circuit, then this is the formula to use.

It is good to note that voltage is read by a voltmeter and comes out from the battery.