Transfer of Charges

Q.

Define charge.

Q. What happens when a negatively charged body is connected to the ground?

1. Earth supplies protons to neutralise the body.
2. Earth takes excess electrons from the body to neutralize it.
3. The body induces negative charges in Earth.
4. Nothing happens and the body remains the same.

Q. Two point charge of +3 micro coulomb and +4 micro coulomb repel each other with a force of 10N. If each is given an additional charge of -6 micro coulomb, the the new force will be?

Q.

Which of the following cannot be charged by rubbing it with neutral bodies?

1. An inflated balloon

2. A woollen cloth

3. A plastic scale

4. A copper rod

Q.

Can you charge an insulator by the method of conduction?

Q.

What happens when we touch the metal top of a charged electroscope with our finger ? What is this process known as ?

Q.

Question 14

The aluminium strips in an electroscope as shown in the figure are replaced by plastic strips and a charged body is brought in contact with the metal clip. what will happen?

Q.

Assertion(A): An electroscope can be used to find the nature of charge on a body.
Reason(R): It is based on the principle: electric charge can be transferred from a charged object to another body.

1. Both A and R are true and R is the correct explanation of A

2. A is true but R is false

3. A is false but R is true

4. Both A and R are true but R is not the correct explanation of A

Q.

Assertion: Mass of a body decreases slightly when it is negatively charged.

Reason: Charging is due to the transfer of electrons.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion

2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion

3. The assertion is correct but the Reason is incorrect

4. The assertion is incorrect but the Reason is correct

Q.

Why charge inside a conductor is zero ?

Q.

What happens when a neutral body is brought in contact with a negatively charged body?

1. it becomes positively charged

2. it becomes negatively charged

3. the net charge is zero

4. it consists of equal positive and negative charges

Q.

What will you observe when the metal top of an electroscope is touched with a glass rod which has been rubbed with silk cloth ? Give reason for your answer.

Q.

Fill the following table.

"$$\begin{array}{cccc}Objectsrubbed& Materialusedforrubbing& Attracts/doesnotattractpiecesofpaper& Charged/notcharged\\ Refill& polythene,woollencloth& & \\ Balloon& polythene,woollencloth,dryhair& & \\ Eraser& wool& & \\ Steelspoon& polythene,woolencloth& & \end{array}$$ "

Q.

When a positively charged body is brought near a conductor, it induces a ______ charge on the near end of the conductor.

Q.

Why does a plastic comb rubbed with dry hair attract bits of paper?

Q.

What will you observe when the metal top of an electroscope is touched with a plastic comb rubbed in dry hair ? Give reason for your answer.

Q.

Charging a neutral by touching it is called charging by __________.

Q.

A metal rod A is to be charged positively by using another charged rod B. What should be the kind of charge on the rod B if charging is to be done by conduction?

Q.

Electric sparks due to lightning have the same phenomenon as that of the sparks when one takes off the woolen clothes.

1. True

2. False

Q.

The flow of electrons isknown as electric current. Then why the way in which electrons flow is different from the way in which the electric current flows.

Q. If two electrically neutral materials A and B are rubbed together and A gets positively charged, it means:

1. A has gained some electrons from B.
2. A has lost some electrons to B.
3. A has gained some protons from B.
4. A has lost some protons to B.

Q.

If the electrons of atoms repel each other than how does adhesive force exist

Q. An uncharged body is brought closer to a positively charged body for sometime. What can be said about in this case?

1. The uncharged body will acquire a negative charge.
2. The uncharged body will remain neutral.
3. The uncharged body will acquire a positive charge.
4. Data insufficient

Q.

Electric sparks due to lightning/thunderstorm and the sparks when one takes off woollen clothes are essentially the same phenomena.

1. False

2. True

Q.

When charges move, they constitute a/an ___.

1. electric current

2. None of the above

3. pressure wave

4. heat wave

Q.

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.

Q.

Which of the following are transferred from one object to another when these two objects are charged by friction?

(a) atoms (b) protons (c) neutrons (d) electrons

Q.

Write two characteristics of electric charges.

Q.

An inflated balloon is rubbed with a woollen cloth and in another case, a ballpen refill is rubbed with polythene. When the balloon and refill are brought closer, it is observed that they attract each other. What can we understand by this?

1. They acquired different kinds of charges

2. One of the object is not charged

3. None of these

4. Both acquired same kind of charge

Q. You are provided with s positively charged gold leaf electroscope. State what happens when:
1) A glass rod rubbed with a silk is brought near the disc of electroscope.
2) A glass rod rubbed with silk is rolled on the disc of electroscope.
3) An uncharged metal rod is brought near the disc of electroscope.