A piece of paper appears to be attracted to a charged ebonite rod, even before they touch (see fig.). The charge at A is :

positive

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

negative

No worries! We‘ve got your back. Try BYJU‘S free classes today!

no charge

No worries! We‘ve got your back. Try BYJU‘S free classes today!

may be positive or negative

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is A positive
Electrostatic induction is a redistribution of electrical charge in an object, caused by the influence of nearby charges without even touching each other. In the presence of a charged body, an insulated conductor develops a positive charge on one end and a negative charge on the other end.
In this case, A piece of paper appears to be attracted to a charged ebonite rod, even before they touch is because of induction. In the figure it is given that the ebonite rod is negatively charged. The point A will be attracted only if the charge at that point is positive because only unlike charges attract each other.
Hence, the charge at A is positive.

Suggest Corrections

Similar questions

Q. A piece of paper appears to be attracted to a charged ebonite rod, even before they touch (see fig.). The above happens because of :

A negatively charged ebonite rod is touched with the disc of a negatively charged gold leaf electroscope. What will be your observation?

Fig.8.37 below shows a metal rod AB placed on an insulating stand. In Fig. (a), a negatively charged ebonite rod C is touched with the metal rod AB, while in Fig.(b), the negatively charged ebonite rod C is held near the rod AB. State the kind of charges at the ends A and B of the rod, in each case.

Write true or false for each statement:

(a) The number of electrons and protons in an atom are same.

(b) If the charge is not in motion, we call it static electricity.

(d) When an ebonite rod is rubbed with fur, the electrons move from ebonite to fur.

(e) When a glass rod is rubbed with the dry silk cloth, the electrons move from glass to silk.

(f) The cap of gold leaf electroscope is made of copper.

(g) If a glass rod rubbed with silk is brought near the cap of a negatively charged electroscope, the divergence of leaves will decrease.

(h) In induction, a positively charged body can make an uncharged body positively charged.

(i) A lighting conductor saves the building from lighting.

(j) When a comb is rubbed with dry hair both comb and paper get similarly charged.

(k) A glass rod rubbed with silk repels an ebonite rod rubbed with fur.

(l) When an ebonite rod is rubbed with fur, the protons move from the ebonite rod to the fur.

(m) A conductor has a large number of free electrons.

(n) An ebonite rod can be charged by touching it with a charged copper rod.

(o) To find whether a body is charged or not, an uncharged electroscope is used.

(p) To find whether the charge on a body is positive or negative, an uncharged electroscope is used.

(q) If a negatively charged rod is brought near a negatively charged pith ball electroscope, the pith ball will be stuck with the rod.

Q. Why can't ebonite be charged by touching it with a charged copper rod ?

Join BYJU'S Learning Program