Two point charges `q_(A) = 3 mu C` and `q_(B) = -3 muC` are located 20 cm apart in vaccum (a) what is the electric field at the mid point O of the line AB joining the two charges ? (b) If a negative test charge of magnitude `1.5xx10^(-9) C` is placed at the point, what is the force experienced by the test charge ?

Explanation

To solve the problem step by step, we will break it down into two parts as given in the question.

### Part (a): Electric Field at Midpoint O

1. **Identify the Charges and Their Positions**:
- Charge \( q_A = 3 \, \mu C = 3 \times 10^{-6} \, C \) is located at point A.
- Charge \( q_B = -3 \, \mu C = -3 \times 10^{-6} \, C \) is located at point B.
- The distance between the charges A and B is \( 20 \, cm = 0.2 \, m \).
...