Asource charge generates an electric field of 1236 n/c at a distance of 4 m. what is the magnitude of the source charge?

2.2 µc
680 µc
2.2 c
680 c

The correct answer to the question is-  

CALCULATION:

As per the question, the electric field generated by the source charge is 1236  N/C at a distance of 4 m.

Hence , electric field  E =  1236 N/C.

The distance of the point R = 4m

We are asked to calculate the charge possessed by the source.

The electric field produced by a source charge of Q at a distance R is calculated as -

                    Electric field E =

Here, is called the absolute permittivity of the free space.

Hence, the charge of source is calculated as -

                                         Q =

                                            =

                                            =

                                             =

                                             =

Hence, the charge of source is

The electric field produced by a charge is given by:

where

k is the Coulomb's constant

q is the charge that produces the field

r is the distance from the charge

In this problem, the magnitude of the electric field is and the distance is r=4 m, so we can rearrange the previous equation to find the magnitude of the charge:

so, the correct answer is 2.2 µC.