Target Exam

CUET

Subject

Physics

Chapter

Electric Charges and Fields

Question:

Case: Read the passage and answer the following questions

A metal rod held in hand and rubbed with wool will not show any sign of being charged. However, if a metal rod with a wooden or plastic handle is rubbed without touching its metal part, it shows signs of charging. Suppose we connect one end of a copper wire to a neutral pith ball and the other end to a negatively charged plastic rod. We will find that the pith ball acquires a negative charge. If a similar experiment is repeated with a nylon thread or a rubber band, no transfer of charge will take place from the plastic rod to the pith ball.

Statement 1: When some charge is transferred to a conductor, it readily gets distributed over the entire surface of the conductor.

Statement 2: In contrast, if some charge is put on an insulator, it distributes up to a certain point and then stays at the same place.

Options:

Both statements are true

Statement 1 is true, but 2 is false

Both statement are false

Statement 2 is true, but 1 is false

Correct Answer:

Statement 1 is true, but 2 is false

Explanation:

Conductors have free electrons,When some charge is transferred to the surface of conductor, the charge is distributed uniformly on the surface.  For example- Metals such as Iron , silver, aluminium etc.

In an insulator, the charge cannot be redistributed. If we charge an insulator, the charge will remain only at the spot that we charged.If the charge is transferred to an insulator at a given location, the excess charge will remain at the initial location of charging. The particles of the insulator do not permit the free flow of electrons; subsequently, charge is seldom distributed evenly across the surface of an insulator.