a
a
b
b
a
b
a
This will really help you learn a lot.
Answer:
C. 
Explanation:
Let initial charges on both spheres be,

When the sphere C is touched by A, the final charges on both will be,
#Now, when C is touched by B, the final charges on both of them will be:

Now the force between A and B is calculated as:

Hence the electrostatic force becomes 3F/8
Answer:
As atoms in the spoon vibrates about their equilibrium positions and transfer energy form one end to other end. This process is called conduction.