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प्रश्न
Which device is used to produce electricity? Describe with a neat diagram.
पर्याय
Electric motor
Galvanometer
Electric Generator (DC)
Voltmeter
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उत्तर
Electric Generator (DC)
Explanation:
The device used for producing electricity is Electric generator (DC). It is based on the phenomenon of electromagnetic induction.
Working:
- The axle is rotated with a machine from outside. When the armature coil of the generator rotates in the magnetic field, electric potential difference is produced in the coil due to electromagnetic induction. This produces a current as shown by the glowing of the bulb or by a galvanometer. The direction of the current depends on the sense of rotation of the coil.
- In a DC generator, one brush is always in contact with the arm of the coil moving up while the other brush is in contact with the arm of the coil moving down in the magnetic field. Hence, the flow of the current in the circuit is always in the same direction and the current flows so long as the coil continues to rotate in the magnetic field.
- In this arrangement, brush A always remains in contact with the length moving up, whereas brush B always remains in contact with the length moving down. Here, split rings C and D act as a commutator. In this case, the direction of the current induced in the coil will be from M to T via N and S for the first half-rotation, and from T to M via S and N for the second half-rotation of coil MNST. Hence, we get a unidirectional current called direct current (DC).
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संबंधित प्रश्न
Draw figure ‘Electric motor’ and working
What is the Principle of an Electric motor?
Name any four appliances where electric motor is used.
State whether the following statement is true or false.
An electric motor converts mechanical energy into electrical energy.
Name some devices in which electric motors are used
Explain the construction and working of an electric motor.
Explain the function of the following parts of an electric motor.
Armature
Explain the function of the following parts of an electric motor.
Brushes
Label the four parts of an electric motor
A motor converts one form of energy into another. Name the two forms.
State whether the following statement is true or false:
An electric motor converts mechanical energy into electrical energy.
Of what substance are the brushes of an electric motor made?
Of what substance is the core of the coil of an electric motor made?
In an electric motor, which of the following remains fixed and which rotates with the coil?
Commutator ; Brush
What is the role of the spilt ring in an electric motor?
What is the principle of an electric motor?
In a d.c. motor, why must the current to the coil be reversed twice during each rotation?
State what would happen to the direction of rotation of a motor if:
both current and magnetic field were reversed simultaneously.
What are the special features of commercial electric motors?
In an electric motor, the direction of current in the coil changes once in each:
two rotations
one rotation
half rotation
one-four rotation
An electric motor is a device which transforms:
mechanical energy to electrical
heat energy to electrical energy
electrical energy to heat energy only
electrical energy to mechanical energy
Name some of the devices in which electric motor are used.
In which electric motor appliances do we use it?
Which of the following converts electrical energy into mechanical energy?
An electric motor converts ______.
State whether true or false. If false, correct the statement.
The speed of rotation of an electric motor can be increased by decreasing the area of the coil.
List the main parts of an electric motor.
An electric motor is a device which transforms ____________.
In an electric motor, to make the coil rotating continuously in the same direction, the current is reversed in the coil after every half rotation by a device called ____________.
The most suitable material for making permanent magnets is ______.
The moving part of an electric motor is called ______.
