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InterviewSolution
| 1. |
Differentiate between AC and DC generator |
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| Answer» | \t1DefinitionAC generator is a mechanical device which converts mechanical energy into AC electrical power.DC generator is a mechanical device which converts mechanical energy into DC electrical power.2Direction of CurrentIn an AC generator, the electrical current reverses direction periodically.In a DC generator, the electrical current flows only in one direction.3Basic DesignIn an AC generator, the coil through which the current flows is fixed while the magnet moves. The construction is simple and costs are less.In a DC generator, the coil through which the current flows rotates in a fixed field. The overall design is very simple but construction is complex due commutators and slip rings.4CommutatorsAC generator does not have commutators.DC generators have commutators to make the current flow in one direction only.5RingsAC generators have slip-rings.DC generators have split-ring commutators.6Efficiency of BrushesSince slip-rings have a smooth and uninterrupted surface, they do not wear quickly and are highly efficient.Both brushes and commutators of a DC generator wear out quickly and thus are less efficient.\t | |
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