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प्रश्न
Which device is used to produce electricity? Describe with a neat diagram.
विकल्प
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
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 function of the following parts of an electric motor.
Armature
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.
What is the other name of the split ring used in an electric motor?
What is the function of a commutator in an electric motor made ?
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?
What is the role of the spilt ring in an electric motor?
What is the principle of an electric motor?
State what would happen to the direction of rotation of a motor if:
the current were reversed
State what would happen to the direction of rotation of a motor if:
In what ways can a motor be made more powerful?
What are the special features of commercial electric motors?
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
Tell the odd one out. Give a proper explanation.
Study the following principle and answer the question.
A force is excreted on the current carrying conductor. The direction of this force depends on both the direction of the current and the direction of the magnetic field. This force is maximum when the direction of current is perpendicular to the direction of the magnetic field.
a) By which law we can determine the direction of force excreted on the current carrying conductor.
b) In which electrical equipment this principle is used.
c) Draw a diagram representing construction of this equipment.
d) Write the working of this equipment in brief.
Name some of the devices in which electric motor are used.
Electric motor : converts electrical energy into mechanical energy : : Electric generator : _______
Right or wrong sentence.
Electro chemicals are devices that convert electrical energy into mechanical energy.
Observe the figure and write the answers to the questions asked.
- The construction shown in the figure is of which device?
- Explain the principle on which this device works.
- Write any three uses of this device.
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.
Direction of rotation of a coil in electric motor is determined by ____________.
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 ____________.
Draw a labelled circuit diagram of a simple electric motor and explain its working. In what way these simple electric motors are different from commercial motors?
Draw an appropriate schematic diagram showing common domestic circuits and discuss the importance of fuse. Why is it that a burnt out fuse should be replaced by another fuse of identical rating?
How can the speed of rotation of a coil be increased? Write at least three methods.
The most suitable material for making permanent magnets is ______.
The moving part of an electric motor is called ______.
Define electric motor.
