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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
Draw figure ‘Electric motor’ and working
Name any four appliances where electric motor is used.
Name some devices in which electric motors are used
Label the four parts of an electric motor
State whether the following statement is true or false:
An electric motor converts mechanical energy into electrical energy.
Name the device which is used to reverse the direction of current in the coil of a motor?
What is the other name of the split ring used in an electric motor?
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?
Fill in the following blank with suitable words:
Fleming's Rule for the motor effect uses the .......... hand.
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:
In what ways can a motor be made more powerful?
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
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 : _______
What is an electric motor?
In which electric motor appliances do we use it?
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.
Which of the following converts electrical energy into mechanical energy?
State whether true or false. If false, correct the statement.
A generator converts mechanical energy into electrical energy.
List the main parts of an electric motor.
An electric motor is a device which transforms ____________.
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 ____________.
Material of the core of a strong magnet is ____________.
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?
How can the speed of rotation of a coil be increased? Write at least three methods.
The moving part of an electric motor is called ______.
Define electric motor.
Observe the following diagram and answer the questions.
- Construction of which equipment does the above diagram show?
- On which principle does this equipment work?
- According to which law the coil ABCD rotates?
- Write the law in your own words.
- Where is this equipment used?
