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प्रश्न
Tell the odd one out. Give proper explanation.
Loud speaker, Microphone, Electric motor, Magnet.
विकल्प
Loud speaker
Microphone
Electric motor
Magnet
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उत्तर
Magnet
Explanation:
Others devices are based on the phenomenon of electromagnetism while the magnet is not.
APPEARS IN
संबंधित प्रश्न
Name any four appliances where electric motor is used.
What is the role of the split ring in an electric motor?
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
Explain the function of the following parts of an electric motor.
Brushes
Explain the function of the following parts of an electric motor.
Split ring
Electric motor works on the magnetic effect of electric current.
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.
Name the device which is used to reverse the direction of current in the coil of a 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?
In an electric motor, which of the following remains fixed and which rotates with the coil?
Commutator ; Brush
Fill in the following blank with suitable words:
Fleming's Rule for the motor effect uses the .......... hand.
What is the principle of an electric motor?
State what would happen to the direction of rotation of a motor if:
both current and magnetic field were reversed simultaneously.
In an electric motor, the direction of current in the coil changes once in each:
two rotations
one rotation
half rotation
one-four rotation
Which device is used to produce electricity? Describe with a neat diagram.
Name some of the devices in which electric motor are used.
Draw a labelled diagram of an electric motor.
What is an electric motor?
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.
List the main parts of an electric motor.
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 ______.
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?
