Electric Field Formula with Solved Example

Electric field formula

When a field is surrounded by an electrical charge, it leads to the formation of the electric field. The presence of an electric field is detected only when another charge is brought near due to which there is some reaction or attraction which indicates the presence of the electric field. 

In simple language, the electric field denotes the electric force per unit of charge. Electric field fills up all the space around an electrical charge or a group of charges. 

The formula for calculating electric field charge: 

The electric field formula is used to calculate this course generated due to the electric charge. Thus we have two components of electric field indicating the force in the electric field and Q which is the representative of electric charge. 

The formula for electric field charge given by E is equal to F / Q

If there are two electric charges namely q and Q and their distance is r, then electric force becomes equal to KqQ/r2. 

Thus putting the value of F in E=F/Q, we get E= V/r where v represents the voltage and r represents the distance. 

Solved examples

Example no. 1: If the force in an electric field is 5 Newton and the charge is 6 units, what would be the intensity of the electric field? 

Answer: We know that E is equal to F / Q

In the present case, F= 5 and q= 6*10-6. Therefore E= 8.33 * 105 NC. 

Solved example no. 2: If the charge of an object is -4*10-6 Q and the electric force is 5.5 newtons, what will be the magnitude and direction of the electric force  if the charge becomes -2q? 

Answer: We know that E= F/Q 

In the present case, Q= -2q and F= 5.5 N 

Therefore E= 5.5/ -2 = -2.75 NW. 

Here the direction will be negative and the magnitude will be 2.75.