Question

Fig. above shows two conductors A and B. Their charges and potentials are given in diagram. Flow of current, when both the conductors are joined by a metal wire will be:

• A. B to A
• B. A to B
• C. no flow
• D. none of these.

Answer 1

The correct option is A B to A

The current in the wire is due to the drifting of electrons inside a wire in a direction opposite to the flow of electrons. During their drifting they collide with their atoms vibrating about their mean position and lose some of kinetic energy to the vibrating atoms.
The electrons are negatively charged particles and so, the electrons move towards the positively charged conductor B indicated by 5 C from the negatively charged conductor A indicated by -10 C. The direction of the current is opposite to the direction of the flow of electrons.
Hence, the direction of the flow of current in the metal wire is from B to A.