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प्रश्न
principle of an electric motor ?
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उत्तर
Principle: An electric motor (dc motor) works on the principle that when an electric current is passed through a conductor placed normally in a magnetic field, a force acts on the conductor as a result of which the conductor begins to move and mechanical energy is obtained.
संबंधित प्रश्न
Name two factors on which the strength of magnetic field of an electromagnet depends and state how does it depend on the factors stated by you.
Name the material of core in (a) an electric bell, (b) electromagnet, (c) a d.c. motor, (d) an a.c. generator and (e) a transformer.
Name the type of transformer shown in Fig. What changes will you observe regarding the brightness of the lamp, if
- the number of turns in the secondary is doubled? Explain.
- the part X of the transformer is removed?
- the core of the transformer is made out of copper?
- the A.C. supply is replaced by D.C.?
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.
Electric bell ______.
State the energy change that takes’place in a D. C. motor.
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State the factors, on which depends the magnitude of the force acting on current carrying conductor, when it is kept in a magnetic field perpendicular to it.
What are the factors that govern the magnitude of force acting on a current carrying conductor which is freely suspended in a magnetic field?
State and explain Maxwell’s Cork Screw Rule.
How does a magnetic field set up by a solenoid change when cross-sectional area of solenoid is increased?
