Tag: electricity

Questions Related to electricity

When the ends of metal wire are not connected to a battery

types of cells electricity physics

  1. electrons move from positive electrode to negative electrode.

  2. electrons move from negative electrode to positive electrode.

  3. electrons move in random directions.

  4. protons move in random direction in such a way that their net movement in a unit volume is zero.

Show answer
Correct Option: C
Explanation:

When the ends of the metal wire are not connected to a battery, no electric field is produced inside the wire. Thus no force acts on the electrons in the wire. So the electrons collide with each other and move in random directions.

Nickel Cadmium cells are used in

types of cells electricity physics

  1. very long-life applications

  2. devices with high limitation on spaces.

  3. portable machines that run on electricity.

  4. all of the above

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Correct Option: C
Explanation:

Nickel cadmium cells are used in portable machines that run on electricity. It is rechargeable.

Button cell is also called as

types of cells electricity physics

  1. lithium cell.

  2. nickel-cadmium cell

  3. dry cell

  4. leclanche cell

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Correct Option: A
Explanation:

Lithium cell has a negative plate of lithium iron phosphate and a positive plate of carbon. It is also called as button cell.

When an electron moves from negative electrode to positive electrode

types of cells electricity physics

  1. negative charge moves from negative electrode to positive electrode.

  2. positive charge moves from positive electrode to negative electrode.

  3. no charge flows from either electrode to other electrode.

  4. both A and B

Show answer
Correct Option: D
Explanation:

Electrons are termed as negative charged particles. Thus when electrons move from negative electrode to positive electrode, we say that negative particles move from negative electrode to positive electrode. On the other hand, the positive charges get attracted towards the negative electrode, thus they move from positive electrode to negative electrode.

Which one works with the help of dry cell?

types of cells electricity physics

  1. Torches

  2. Transistors, toys

  3. T.V.remotes

  4. All of these

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Correct Option: D

State whether true or false:
The used up chemicals in a dry cell can be re-obtained by charging it.

types of cells electricity physics

  1. True

  2. False

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Correct Option: B
Explanation:

Dry cell are not rechargeable.

Out of the following the one which is a source of e.m.f is:

types of cells electricity physics

  1. voltaic cell

  2. dynamo

  3. thermocouple

  4. lous speaker

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Correct Option: A
Explanation:

A voltaic cell is an electrochemical cell that produces electrical energy. In voltaic cell there is an anode where oxidation occurs and a cathode where reduction occurs. So, it produces current and thus emf is produced in voltaic cells.

For a cell reaction involing a two-electron change, the standard e.m.f of the cell is fonud to be$0.295V$ at $25^{o}C$. The equilibrium constant of the reaction at $25^{o}C$ will be:

types of cells electricity physics

  1. $10$

  2. $1\ \times 10^{10}$

  3. $1\ \times 10^{-10}$

  4. $29.5\ \times 10^{-2}$

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Correct Option: D

The electric cell is a device to obtain ?

types of cells electricity physics

  1. electric charge

  2. electric force

  3. electrons

  4. electric energy from chemical energy

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Correct Option: D
Explanation:

It is a common misconception that battery or cell delivers charge but this is not true at all.The battery as a whole is electrically neutral and its only job is to provide electrical energy.This is usually done using conversion of chemical energy to electric energy.

An electrochemical cell stops working after some time because

types of cells electricity physics

  1. Electrode potential of both the electrodes become zero.

  2. Electrode potential of both the electrodes become equal.

  3. One of the electrode is eaten away.

  4. The reaction starts proceeding in opposite direction.

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Correct Option: A