## Answer :

1.

**Understand the given data:**

- We have an electric field [tex]\( E \)[/tex] with a magnitude of [tex]\( 20 \, \text{N/C} \)[/tex].

- There's a point charge [tex]\( Q \)[/tex] at a certain distance [tex]\( r \)[/tex] from the source charge.

- The distance given from the charge Q to the point is [tex]\( 2 \, \text{m} \)[/tex].

- There is a test charge [tex]\( q \)[/tex] of [tex]\( 5 \, \text{C} \)[/tex] placed in this electric field.

2.

**Objective:**

- We need to calculate the force [tex]\( F \)[/tex] exerted by the electric field on the test charge [tex]\( q \)[/tex].

3.

**Use the relationship between force, electric field, and charge:**

- The relationship between the electric field [tex]\( E \)[/tex], the force [tex]\( F \)[/tex], and the charge [tex]\( q \)[/tex] is given by the formula:

[tex]\[ F = q \cdot E \][/tex]

4.

**Substitute the known values into the formula:**

- The electric field [tex]\( E \)[/tex] is [tex]\( 20 \, \text{N/C} \)[/tex].

- The test charge [tex]\( q \)[/tex] is [tex]\( 5 \, \text{C} \)[/tex].

[tex]\[ F = 5 \, \text{C} \times 20 \, \text{N/C} \][/tex]

5.

**Calculate the force:**

[tex]\[ F = 100 \, \text{N} \][/tex]

Therefore, the force exerted by the electric field on a charge of [tex]\( 5 \, \text{C} \)[/tex] is [tex]\( 100 \, \text{N} \)[/tex].