Tag: physics

Questions Related to physics

When a glass rod is rubbed with a piece of silk cloth the rod

physics static electricity explaining static electricity charging by induction electric charges and fields

  1. and the cloth both acquire positive charge

  2. becomes positively charged while the cloth has a negative charge

  3. and the cloth both acquire negative charge

  4. becomes negatively charged while the cloth has a positive charge

Show answer
Correct Option: B
Explanation:

Answer is B.

Negative electrification is due to the excess of electrons (compared to the normal number of electrons in a neutral atom).For example, on rubbing a glass rod with silk, the electrons from the glass rod get transferred to the silk. The silk now has an excess of electrons and so is negatively-charged. On the other hand, the glass rod is deficient in electrons and hence is positively-charged.
In the above example, the silk undergoes negative electrification.
Hence, the glass rod becomes positively charged while the silk cloth has a negative charge.

When a glass rod is rubbed with silk

physics static electricity explaining static electricity charging by induction electric charges and fields

  1. Negative charge is produced on silk but not charge on the glass rod

  2. Equal but opposite charge are produced on the both

  3. Equal and similar charges are produced on the both

  4. Positive charge is produced on the glass rod but no charge on the silk

Show answer
Correct Option: B
Explanation:

When glass rod is rubbed with silk, glass happens to lose electrons easily and silk grabs them away from the glass atoms. So after rubbing, the glass becomes positively charged and the silk becomes negatively charged.

Thus equal but opposite charge are produced on the both.
Hence, option B is correct.

A hollow metallic sphere is charged. Inside the sphere

physics static electricity explaining static electricity charging by induction electric charges and fields

  1. The potential is zero but the electric field is finite

  2. The electric field is zero but the potential is finite

  3. Both the electric field and the potential are finite

  4. Both the electric field and the potential are zero

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Correct Option: B

When a glass rod is rubbed with silk, it is said to be positively charged. Which of the following statement is true?

physics static electricity explaining static electricity charging by induction electric charges and fields

  1. Electrons move from silk to glass

  2. Electrons move from glass to silk

  3. Protons move from silk to glass

  4. Protons move from glass to silk

Show answer
Correct Option: B
Explanation:

When a glass rod is rubbed with silk, it acquires a positive charge, means it is deficit of electrons i.e, electrons move from glass to silk. So glass rod becomes positively charged and silk rod is negatively charged.

Two uncharged bodies when rubbed against each other get charged. This is known as

physics static electricity explaining static electricity charging by induction electric charges and fields

  1. Charging by conduction

  2. Charging by friction

  3. Charging by induction

  4. Charging by convection

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Correct Option: B
Explanation:

Charging by friction refers to generation of charge on uncharged bodies when rubbed against each other. One of the rubbed material loses electrons and becomes positively charged and other material gains that electron and becomes negatively charged.

When a plastic comb rubbed on hair is brought near bits of paper, it attracts them because:

physics static electricity explaining static electricity charging by induction electric charges and fields

  1. The comb and the paper get similarly charged.

  2. They get oppositely charged.

  3. The paper bits are very light.

  4. None of these

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Correct Option: B
Explanation:

A comb rubbed on hair gets electrically charged. It attracts small bits of paper because opposite charges attract. So, comb and bits of paper are oppositely charged.

If a body is charged by rubbing it, its weight _________.

physics static electricity explaining static electricity charging by induction electric charges and fields

  1. Remains precisely constant

  2. Increases slightly

  3. Decreases slightly

  4. May increase or decrease slightly

Show answer
Correct Option: D
Explanation:

If a body is charged by rubbing it, then it may lose or gain electrons. Since electrons have a mass of $(9.1\times 10^{-31} :Kg)$. So, a slight weight may increase or decrease slightly.

The process suitable for charging a glass rod is :

physics static electricity explaining static electricity charging by induction electric charges and fields

  1. conduction

  2. induction

  3. rubbing against a suitable substance

  4. all of the above

Show answer
Correct Option: C
Explanation:

The process suitable for  charging a glass rod is by friction,means by rubbing against a suitable substance.


Option C is correct.

During electrification by friction

physics electric charges and fields explaining static electricity charging by induction static electricity

  1. Proton are transferred from one body to another body

  2. Neutrons are transferred from one body to another body

  3. Electrons are transferred from one body to another body

  4. None

Show answer
Correct Option: C
Explanation:

When a body is rubbed over another,transfer of electrons from one body to another. Thus one body acquires a net positive charge and the other acquires net negative charge.proton and neutron are packed in the nucleus thus they cannot move.

example - When a glass rod is rubbed with a silk cloth some electrons from the glass attach themselves to the silk. Consequently, the glass becomes positively charged and the silk negatively charged. Likewise when ebonite is rubbed with fur electrons are transferred from fur to ebonite, thus making the ebonite negative and the fur positive.

Option C is correct.

An ebonite rod rubbed with fur and a glass rod rubbed with silk cloth are brought nearer to each other. Then

physics static electricity explaining static electricity charging by induction electric charges and fields

  1. they will attract each other

  2. they will repel each other

  3. nothing will happen to them

  4. they will get heated up

Show answer
Correct Option: A
Explanation:

When an ebonite rod is rubbed with fur, the ebonite rod gets negatively charged and the fur becomes positively charged. Whereas when a glass rod is rubbed with silk cloth, the glass rod becomes positively charged and the silk cloth becomes negatively charged.

Now as we know that unlike charges attract each other, thus the glass rod and the ebonite rod will attract each other as they have opposite charges.