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प्रश्न
What is an electric motor?
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उत्तर
Electric motor : An electric motor is a device which converts the electrical energy into the mechanical energy.
संबंधित प्रश्न
The diagram shows a coil wound around a U-shaped soft iron bar AB.
- What is the polarity induced at the ends A and B when the switch is pressed?
- Suggest one way to strengthen the magnetic field in the electromagnet.
- What will be the polarities at A and B if the direction of current is reversed in the circuit?
principle of an electric motor ?
Fill in the blanks by writing (i) Only soft iron, (ii) Only steel, (iii) Both soft-iron and steel for the material of core and/or magnet.
Electromagnet ______.
Complete the following sentence :
On reserving the direction of current in a wire, the magnetic field produced by it gets _____.
The magnetic flux through a coil having 100 turns decreases from 5 milli weber to zero in 5 second. Calculate the e.m.f. induced in the coil.
State two factors on which the strength of induced e. m.f. depends.
Describe briefly one way of producing an induced current in a coil. State one factor that determines the magnitude of induced e.m.f.
A straight current-carrying conductor is kept in a magnetic field. It Experiences a force. State three factors on which the magnitude of force Experienced by the conductor depends. Under what condition will the conductor Experience no force?
What will be the effect on the working of an electric bell if instead of a direct current an alternating current is used?
State the factors that can increase the speed of rotation of the coil in a D.C. motor.
