Charge & Electric Field

1. A charge q is placed at the centre of the line joining two equal
charges Q. The system of the three charges will be in equilibrium
if q is equal to

 
 
 
 

2. Three point charges are placed at the corners of an equilateral
triangle. Assume that only electrostatic forces are acting.

 
 
 
 

3. In the previous question, the equilibrium is

 
 
 
 

4. Two particles, each of mass m and carrying charge Q, are
separated by some distance. If they are in equilibrium under
mutual gravitational and electrostatic forces then Q/m (in C/kg)
is of the order of

 
 
 
 

5. Three point charges are placed at the corners of an equilateral
triangle. Assume that only electrostatic forces are acting.

 
 
 
 

6. Charge Q is divided into two parts which are then kept some
distance apart. The force between them will be maximum if the
two parts are

 
 
 
 

7. A point charge Q is moved along a circular path around another
fixed point charge. The work done is zero

 
 
 
 

8. Two identical metal balls with charges +2Q and Q are separated
by some distance, and exert a force F on each other. They are
joined by a conducting wire, which is then removed. The force
between them will now be

 
 
 
 

Question 1 of 8