Tag: physics

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

What happens when two straws are individually rubbed with separate sheets of paper and are brought near to each other?

  1. The straws attract each other

  2. The straws repel each other

  3. The straws remain indifferent of each other

  4. Either A or B
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

It is because both the object are rubbed with a sheet of paper and they acquires same charges so they repels each other. 

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

When the ebonite rod is rubbed with fur, the charge acquired by the fur is:

  1. negative

  2. positive

  3. both positive and negative

  4. none of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When an ebonite rod is rubbed with fur, electrons are transferred from the fur to the ebonite rod. Since the fur loses electrons, it acquires a positive charge, while the ebonite rod becomes negatively charged.

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

Electrostatic induction is used to charge

  1. Conductors

  2. Semiconductors

  3. Insulators

  4. All of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
The presence of electric charges on the insulator and the electric charges on the insulator and the electric forces they apply to the conduction electrons - creates or induces, the dipole in the conductor. This produces electrostatic charge on conductors.
Multiple choice physics static electricity explaining static electricity charging by induction electric charges and fields

Two bodies are changed by rubbing one against the other. During the process, one becomes positively charged while the other becomes negatively charged. Then,

  1. mass of each body remains unchanged.

  2. mass of each body changes marginally.

  3. mass of each body changes slightly and hence the total mass.

  4. mass of each body changes slightly but the total mass remains the same.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
The transfer of electrons from one body to the result in redistribution of charges.
Hence, no. of electrons given by one body $=$ Number of electrons obtained by the other.
$\therefore$ Mass of negatively charged body slightly increases.
Whereas the total mass of the system remain the same.
Multiple choice physics static electricity explaining static electricity charging by induction electric charges and fields

Which of the following statement is NOT true?

  1. Lightning and spark from woolen clothing are essentially the same phenomena.

  2. When you rub a plastic scale on your dry hair, it acquires a charge.

  3. Charge acquired by a glass rod when it is rubbed with silk is negative charge.

  4. Static charges are called so, because they do not move by themselves.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Benjamin Franklin showed for the first time that lightning and spark from our clothes are essentially the same phenomena.

When a plastic scale is rubbed with dry hair, it acquires a small charge. These objects are called charged objects. In the process of charging the plastic scale hair also get charged.
When you are rubbing the glass rod with the silk cloth, electrons are stripped away from the atoms in the glass and transferred to the silk cloth. This leaves the glass rod with more positive than negative charge, so you get a net positive charge.

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

A glass rod is rubbed with silk, is found positively charged. This is because.

  1. Electrons are transferred from glass rod to silk.

  2. Electrons are transferred from silk to glass rod.

  3. Protons are transferred from glass rod to silk.

  4. Protons are transferred from silk to glass rod.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

When you are rubbing the glass rod with silk cloth, electrons are stripped away from the atoms in the glass and transferred to the silk cloth.

Hence, option A is correct.

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

What causes electrification of two bodies when they are rubbed together ?

  1. Transfer of atoms from one body to the other body.

  2. Transfer of electricity from one body to the other body.

  3. Transfer of electrons from one body to the other body.

  4. Transfer of heat from one body to the other body.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Electrification is defined as the transfer of electrons from one body to another when they are rubbed with each other.

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.

Positive electrification is due to the deficiency of electrons (compared to the normal number of electrons in a neutral atom).
For example, on rubbing an ebonite rod with fur or cat's skin, the electrons from the cat's skin get transferred to the ebonite rod. The cat's skin now has a deficiency of electrons and so is positively-charged. On the other hand, the ebonite rod has an excess of electrons and hence is negatively-charged. In the above example, the cat's skin undergoes positive electrification. It should be noted that it is the electrons and not the protons that get transferred during positive (and negative) electrification.

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

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

  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
Reveal answer Fill a bubble to check yourself
B Correct answer
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.