A pendulum bob has mass 4 mg and carrieas a charge `2xx10^(-9)` coulomb. It hangs in equilibrium from a massless thread of length 50 cm whose other end is fixed to a vertical wall. A horizontal electtic field of inetensity 20000 V/m exists in space. Calculate
a. Angle made by the thread with the vertical
b. Tension in the thread

Explanation

To solve the problem step by step, we will calculate the angle made by the thread with the vertical and the tension in the thread.

### Given Data:
- Mass of the pendulum bob, \( m = 4 \, \text{mg} = 4 \times 10^{-6} \, \text{kg} \)
- Charge on the bob, \( q = 2 \times 10^{-9} \, \text{C} \)
- Length of the thread, \( L = 50 \, \text{cm} = 0.5 \, \text{m} \)
- Electric field intensity, \( E = 20000 \, \text{V/m} \)
- Acceleration due to gravity, \( g = 10 \, \text{m/s}^2 \)
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