A very tiny ball of mass 20 g carries a positive charge `0.04 muC` . It is held stationary in air due to electric force by a charge fixed below it at a distance of 10 cm. What should be the magnitude and nature of charge ?

Explanation

To solve the problem, we need to find the magnitude and nature of the charge \( q_0 \) that is fixed below a tiny ball with a mass of 20 g and a positive charge of \( 0.04 \, \mu C \) (microcoulombs). The ball is held stationary due to the electric force exerted by the charge \( q_0 \) at a distance of 10 cm (0.1 m).

### Step-by-Step Solution:

1. **Convert Mass to Kilograms**:
The mass of the ball is given as 20 g. We need to convert this to kilograms:
\[
m = 20 \, \text{g} = \frac{20}{1000} \, \text{kg} = 0.02 \, \text{kg}
...