Answer:
The energy stored is 1.4 x 10^-9 J.
Explanation:
Side of square, L = 10 cm = 0.1 m
Distance, d = 2 mm = 0.002 m
Electric field, E = 4000 V/m
The energy stored in the capacitor is

The capacitance is given by

Given that,
Height =1.5 m
Angle = 45°
We need to find the greater speed of the ball
Using conservation of energy


Here, initial velocity and final potential energy is zero.

Put the value into the formula




Hence, the greater speed of the ball is 5.42 m/s.
Answer: Electric current
Explanation :
The direction of the magnetic field produced by an electric current will change when the direction of the electric current changes.
For example :
If a current is flowing in a straight length of wire, the magnetic field is described by a concentric circle (using right-hand rule).
Let the field lines are in the clockwise direction and when the direction of current is reversed then the direction of the magnetic field is in anticlockwise direction.