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InterviewSolution
| 1. |
What is the working of electric motor and generator |
| Answer» Working of electric motor:\tWhen electric current is passed into the rectangular coil, this current produces a magnetic field around the coil.\tThe magnetic field of horse shoe-type magnet then interacts with the magnetic field of the coil and causes the coil to rotate continuously.\tIf ABCD is in horizontal position current from battery enters the coil through brush B1, and commutator half ring C:. The current flows in the direction ABCD\tand leaves via ring and brush B2\xa0\tThe direction of current is from A to B, the direction of current is from C to D. The force on side AB of the coil is in the downward direction. Whereas the force on the side CD of the coil is in the upward direction. ABCD rotate in anti-clockwise direction.\tWhile rotating when the coil reaches vertical position then the brushes B1 and B2 will touch the gap between the commutator rings and current to the coil is cut off. But the coil does not stop rotating because it has already gained momentum.\tThe coil CD comes on the left side and AB comes to the right side. Again they come in contact with brush B1 Current direction is reversed.\tThe reversing of current in the coil is repeated after every half rotation due to which the coil continue to rotate as long as current from the batter is passed through it. The rotating shaft of electric motor can drive a large number of machines which are connected to it.Electric Generator\tThe axle is rotated such that it moves in the clockwise directions that is AB moves up and CD moves down.\tAccording to Fleming\'s Right Hand rule, the induced current is setup in the coil along B1-> AB -> BC -> CD -> B2. This means that the external current flows from B2 to B1.\tAfter half a rotation, arm CD starts moves up and AB moves down.\tAccording to Fleming\'s Right Hand rule, the induced current is setup in the coil along B2-> AB -> BC -> CD -> B1. This means that the external current flows from B1 to B2.\tThus after every half rotation of the coil, the current changes direction. This is called an AC current.\tAC current(Alternating current) : Changes its direction after equal intervals of time. It is easier to transmit this current over long distances due to lesser loses and hence this is the current that is supplied to our houses from the electricity department. | |