Current Formula


Before proceeding to learn about the current formula, let us recall what current means. Current is defined as the flow of electrons in an electric circuit. The flow of electrons occurs due to potential differences. The current is also known as the rate of change of charge with time. Current is represented by I and SI unit of current is Ampere. The current formula is derived from the Ohms law and is explained in the section below.

What Is the Current Formula?

According to Ohm's law, the current is the ratio of the potential difference and the resistance. Thus, the current formula is given by:

I = V/R

Where

  • I is the current in Ampere,
  • V is the potential difference in Volt
  • R is the resistance in Ohm(Ω). 

Let us see the applications of the current formula in the following solved examples section.

Solved Examples Using Current Formula

Example 1: In an electric circuit, the potential difference and the resistance are given as 20V and 4Ω respectively. Find the current flowing in the circuit.

Solution:      

To find: Current(I) flowing in the circuit.

Given:

V = 20V, R = 4Ω

Using Current formula

I = V/R

I = 20/4

I = 5

Answer: Current flowing in the circuit is 5 Ampere.

 

Example 2: The total current flowing in an electric circuit is 50Amp whereas the resistance of the wires is 14Ohm. Find the potential difference.

Solution:     

To find: Potential difference 

Given:

I = 50 A, R = 14Ω

Using Current formula

I = V/R

50 = V/14

V = 50 × 14

V = 700

Answer: Potential difference is 700 V.