What is the strength of the electric field at the position indicated by the dot in the figure?

Question

Let r = 8.0 cm .

Express your answer to two significant figures and include the appropriate units

  

Answer 1

Step 1:

Observe the figure:

The two point charges are positive, hence

The angle of the field at the dot from the top charge is .

The angle of the field at the dot from the botton charge is .

Electric field due to charged particle is , where

is the permittivity of free space .

is the charge of the electron.

is the distance between the two point charges.

Step 2:

The distance between the top charge and the dot is .

For the charged particle along top surface is .

The distance between the bottom charge and the dot is .

For the charged particle along top surface is .

Step 3:

Find the net electric field.

is sum of horizontal and vertical components.

Find the sum of horizontal components.

Find the sum of vertical components.

Therefore .

Find the magnitude of electric field strength.

Strength of the electric field is

Find the direction of electric field.

Direction of electric field is above the -axis.

Solution:

Strength of the electric field is

Direction of electric field is above the -axis.