Tag: charging by induction

Questions Related to charging by induction

A neutral rubber rod and a neutral piece of fur have equal amounts of negative and positive charge. When the fur is rubbed against the rod, a transfer of electrons occurs. The transfer of electrons and mass transfer respectively takes place from

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

  1. fur to rubber rod; rubber rod to fur

  2. fur to rubber rod; fur to rubber rod

  3. rubber rod to fur; rubber rod to fur

  4. rubber rod to fur; fur to rubber rod

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Correct Option: B
Explanation:

Answer is B.

On rubbing an rubber rod with fur, the electrons from the fur get transferred to the rubber rod. The fur now has a deficiency of electrons and so is positively-charged. On the other hand, the rubber rod has an excess of electrons and hence is negatively-charged.
In the above example, the fur undergoes positive electrification. It is to be noted that it is the electrons and not the protons that get transferred during positive (and negative) electrification.
Here, the transfer of electrons and mass transfer respectively takes place from fur to the rubber rod.

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

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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

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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

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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

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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

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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.