(a) State Fleming's left hand rule. (b) Write the principle of working of an electricmotor. (c ) Explain the function of the followingparts of an electricmotor. (i) Armature , (ii) Brushes , (iii) Split ring

(a) State Fleming's left hand rule. (b) Write the principle of workin

1.	(a) State Fleming's left hand rule. (b) Write the principle of working of an electricmotor. (c ) Explain the function of the followingparts of an electricmotor. (i) Armature , (ii) Brushes , (iii) Split ring
Answer» Solution :(a) Fleming's left hand rule, Accordingto Fleming's left hand rule, hold the forefinger, the centre FINGER and the thumb of your left hand atright anglesto one another. Adjustyour hand in such a waythat the forefingerpoints in the direction of magneticfieldand the centrefinger pointsin the direction of forceacting on the conductor. (b) Principle of anelectric motor. The workingprincipleof an ELECTRICMOTOR is based onthe magenticeffectof current. An electricmotorworkson the principlethat when a rectangularcoil isplacedin a magnetic fieldand currentis passed through it, a forceacts onthe coil whichrotates it continuously. It is based on Fleming's lefthand rule. (c ) (i) Armature . It is the rotating part ofa motor. Armatureis a coil whichcarries currentand rotates in the magenticfield. (ii) Brushes. The function of carbon brushes is to make contact with the rotatingsplit-ringsof the commutatorso as to supply currentto the coil. (iii) Spilt ring.The function of SPLIT rings is to REVERSE the direction of currentflowingthroughthe coil everytime the coil passes the vertical positionduring a REVOLUTION.