Class 10 Physics Magnetic Effects of Electric Current AC Generator

AC Generator

Parts of an AC Electric Generator

• Insulated Copper wire: A rectangular rotating coil of wire ABCD
• Magnet Poles: A magnet as placed above ie North Pole and South Pole. This creates a magnetic field as shown above. The rectangular coil is placed between these magnets
• Split Rings: Two disjoint C-shaped rings R1 and R2 are internally attached to the Axle.. Ends of the coil are connected to R1 and R2. The inner portion of these rins are made of non-conducting material
• Axle: The split rings are placed on the axle which is made to rotate freely from an external source.
• Brushes: The outside of the split rings are connected to conducting brushes B1 and B2. B1 and B2 is kept pressed on R1 and R2 respectively.
• Galvanometer : To measure current. The outer ends of the brushes are connected to the galvanometer to measure the current

Working

• The axle is rotated such that it moves in the clockwise directions that is AB moves up and CD moves down.
• According 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.
• After half a rotation, arm CD starts moves up and AB moves down.
• According 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.
• Thus after every half rotation of the coil, the current changes direction. This is called an AC current.
• AC 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.

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