Question

For the charge distribution provided, indicatethe region (A to E) along the horizontal axis where a point existsat which the net electric field is zero.

If no such region exists on thehorizontal axis choose the last option the region (A to E) alongthe horizontal axis (nowhere).

For the charge distribution provided, indicatethe region (A to E) along the horizontal axis where a point existsat which the net electric field is zero.

If no such region exists on thehorizontal axis choose the last option (nowhere).

For the charge distribution provided, indicatethe region (A to E) along the horizontal axis where a point existsat which the net electric field is zero.

If no such region exists on thehorizontal axis choose the last option (nowhere).

For the charge distribution provided, indicatethe region (A to E) along the horizontal axis where a point existsat which the net electric field is zero.

If no such region exists on thehorizontal axis choose the last option (nowhere).

Answer 1

Concepts and reason

Concept required to solve the given problem is to find the net electric field in a given region by using direction of electric field due a positive charge and direction of electric field due to a negative charge, and by using expression for electric field.

Fundamentals

The electric field in a region is defined as the number of electric field lines passing through that region. The direction of electric field is depends on the direction of electric field lines.

The electric field lines are always directed away from a positive charge. Thus, the direction of electric field due a positive charge is away from the positive charge.

The electric field lines are always directs towards a negative charge. Thus, the direction of electric field due to a negative charge is towards negative charge.

The expression for electric field E due to a charge q at a distance r from the charge is given as follows:

$E = \frac{{kq}}{{{r^2}}}$

Here, k is constant.

From the above expression it can be clear that, the electric field increases with increase in charge, and decreases with increase in distance from the charge.

(A)

Draw the following figure represents the direction of electric field due to both the charges in region A.

From the above figure, it can clear that the net electric field is not zero in region A.

Draw the following figure represents the direction of electric field due to both the charges in region B.

The net electric field is not zero in region B.

Draw the following figure represents the direction of electric field due to both the charges in region B.

The net electric field is not zero in region D.

Draw the following figure represents the direction of electric field due to both the charges in region E.

The electric field is not zero in region E, because the electric field due to both the charges is directed towards right.

Draw the following figure represents the direction of electric field due to both the charges in region E.

The net electric field in region C is zero. Because the both charges have same magnitude and have same distance from the region C and having electric field in opposite directions.

(B)

Draw the following figure represents the direction of electric field due to both the charges in region A.

The net electric field is not zero in region A.

Draw the following figure represents the direction of electric field due to both the charges in region C.

The net electric field is not zero in region C.

Draw the following figure represents the direction of electric field due to both the charges in region D.

The net electric field is not zero in region D.

Draw the following figure represents the direction of electric field due to both the charges in region E.

The net electric field is not zero in region E.

Draw the following figure represents the direction of electric field due to both the charges in region B.

The net electric field is zero in region B, because the magnitude of right charge is greater than that of magnitude of left charge, and left charge is closed to region B.

(C)

Draw the following figure represents the direction of electric field due to both the charges in region A.

The net electric field is not zero in region A.

Draw the following figure represents the direction of electric field due to both the charges in region B.

The net electric field is not zero in region B.

Draw the following figure represents the direction of electric field due to both the charges in region C.

The net electric field is not zero in region C.

Draw the following figure represents the direction of electric field due to both the charges in region D.

The net electric field is not zero in region D.

Draw the following figure represents the direction of electric field due to both the charges in region E.

The net electric field is not zero in region E.

(D)

Draw the following figure represents the direction of electric field due to both the charges in region B.

The net electric field is not zero in region B.

Draw the following figure represents the direction of electric field due to both the charges in region C.

The net electric field is not zero in region C.

Draw the following figure represents the direction of electric field due to both the charges in region D.

The net electric field is not zero in region D.

Draw the following figure represents the direction of electric field due to both the charges in region E.

The net electric field is not zero in region E.

Draw the following figure represents the direction of electric field due to both the charges in region E.

The net electric field is zero in region A.

Ans: Part A

The net electric field is zero in region C.