Tag: effects of electric current

Questions Related to effects of electric current

An electrical generator works on the principle of electromagnetic induction.

physics effects of electric current electric generator ac generator magnetic effects of electric current

  1. True

  2. False

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Correct Option: A
Explanation:

The electric generator works on the principle of Faraday's Law of electromagnetic induction.


Hence, given statement is $True$.

Complete the sentence by using the correct words given in the brackets:

A ________ (generator / transformer/motor/transducer) is a source of electricity that generates large amount of electricity in a power house.

physics effects of electric current electric generator ac generator magnetic effects of electric current

  1. Motor

  2. Generator

  3. Transducer

  4. Transformer

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Correct Option: B
Explanation:

A generator is a device that converts mechanical energy into electrical energy. It is the source of electricity used to generate large amounts of electricity in power house.

In a DC generator, the ends of the coil are connected to __________.

physics effects of electric current electric generator ac generator magnetic effects of electric current

  1. two slip rings

  2. the split ring commutator

  3. either $(1)$ or $(2)$

  4. None of these

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Correct Option: B
Explanation:

In a DC generator, the ends of the coil are connected to the split ring commutator.

If the coil in a simple generator is wound around a soft iron core then:

physics effects of electric current electric generator ac generator magnetic effects of electric current

  1. strength of magnetic field increases.

  2. current produced will be increased.

  3. voltage produced will be increased.

  4. all

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Correct Option: D
Explanation:

Voltage/current produced in a generator can be increased by: 
a) Using a powerful electromagnet to make the magnetic field stronger in place of a permanent magnet.
b) By winding the coil round a soft iron core to increase the strength of magnetic field.
c) By using a coil with more turns.
d) By rotating the coil faster.
e) By using a coil with a larger area.

If we use a powerful electromagnet in place of permanent magnet in a generator, then:

physics effects of electric current electric generator ac generator magnetic effects of electric current

  1. voltage produced by the generator increases.

  2. current produced by the generator increases.

  3. Both A and B are true.

  4. No effect on current or voltage occurs.

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Correct Option: C
Explanation:

If a powerful electromagnet is used instead of a permanent magnet, magnetic field strength increases. This increase in magnetic field strength leads to the increase in induced voltage in the coil. An increased voltage leads to an increased induced current in the generator.

AC generator is also h/a

physics effects of electric current electric generator ac generator magnetic effects of electric current

  1. convertor

  2. invertor

  3. alternator

  4. none

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Correct Option: C
Explanation:

AC generator produces alterating current which reverses its direction continuously. It is also h/a alternator.

Which of the following can't increase the voltage produced by the generator?

physics effects of electric current electric generator ac generator magnetic effects of electric current

  1. Using a powerful electromagnet to make the magnetic field stronger in place of a permanent magnet.

  2. By winding the coil round a soft iron core to increase the strength of magnetic field.

  3. By using a coil with more turns.

  4. Changing the material of the coil.

Show answer
Correct Option: D
Explanation:

Voltage/current produced in a generator can be increased by:
a) Using a powerful electromagnet to make the magnetic field stronger in place of a permanent magnet.
b) By winding the coil round a soft iron core to increase the strength of magnetic field.
c) By using a coil with more turns.
d) By rotating the coil faster.
e) By using a coil with a larger area.

Fleming's left and right hand rule are used in

physics effects of electric current electric generator ac generator magnetic effects of electric current

  1. DC motor and AC motor

  2. DC generator and AC motor

  3. DC motor and DC generator

  4. both rules are same, any one can be used

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Correct Option: C
Explanation:

DC motor is a device which coverts electrical energy into mechanical energy. It employs Fleming's left hand rule.
DC generator converts mechanical energy into electrical energy in from of DC. It employs Fleming's right hand rule.

Generators uses the principle of ________ to push electrons through a wire.

physics effects of electric current electric generator ac generator magnetic effects of electric current

  1. electromagnetic induction

  2. electromagnetic reduction

  3. magnetoelectric conduction

  4. electric induction

  5. magnetic field contraction

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Correct Option: A
Explanation:

The EMF generated by Faraday's law of induction due to relative movement of a circuit and a magnetic field is the phenomenon underlying electrical generators. When a permanent magnet is moved relative to a conductor, or vice versa, an electromotive force is created. If the wire is connected through an electrical load, current will flow, and thus electrical energy is generated, converting the mechanical energy of motion to electrical energy.

A dynamo makes 100 cycles per second. The frequency of the AC is

physics effects of electric current electric generator ac generator magnetic effects of electric current

  1. 100 Hz

  2. 200 Hz

  3. 50 Hz

  4. 400 Hz

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Correct Option: A
Explanation:

The frequency of AC current produced is same as the frequency of rotation of dynamo which is given 100 cycles per second that is $100Hz$.


Hence, answer-(A)