Question

When the resistance of a conductor increases, the current will ________.
(A) Increase
(B) Decrease
(C) Remain the same
(D) None of the above

Answer 1

Hint Current in a conductor is due to motion of the free electrons in it and we all know that a conductor has a large number of free electrons in it. Resistance of any conductor depends on collisions (collisions of particles like electrons) inside the wire itself. Thinking in this direction can lead us to the answer.

Complete step-by-step answer:
Current in a conductor is due to motion of the free electrons in it so, when a potential difference is applied across the ends of a metallic wire, the free electrons begin to drift from the low potential to the high potential region which results in the flow of current inside the wire.

Resistance is defined as the opposition to the flow of electrical current through a conductor. It depends on collisions (collisions of particles like electrons) inside the wire itself.
As electrons move through a metal conductor, some collide with other particles, other atoms, other electrons or the impurities present inside the metal. These collisions cause resistance and generate heat. Heating the metal conductor causes atoms to vibrate more, which in turn makes it more difficult for the electrons to flow, increasing resistance.

Now, if we increase the resistance of the conductor, it means collisions within the wire increase. Electrons will find it more difficult to move due to more collisions with other particles.
This makes us realize that an increase in collisions reducing the flow of electrons, will decrease the current.

Hence the answer is current decreases on an increase in the resistance.

Note If we think practically then the solution of the question is described above. But if we think of theoretically, then a simple, theoretical and direct thinking of the solution can be thinking of the ohm’s law which indirectly states that current is inversely proportional to the resistance of the conductor.