(a) State Fleming's left hand rule ?
b)Write the principle of working of an electric motor?
c) Explain the function of the following parts of as electric motor
) Armature (i) Brushes (ii) Split ring
Answers
Answer:
(a) Fleming's left hand rule can be stated as stretch the forefinger, middle finger and thumb of right hand such that they are mutually perpendicular to each other.If forefinger indicates the direction of magnetic field,middle finger indicate the direction of current in conductor then thumb indicates the direction of force exerted on conductor.
(b) The working principle of electric motor is based on the magnetic effect of current .A current - carrying loop experience a force and so takes when placed magnetic field.The direction of rotation of loop is given by Fleming's left hand rule.
(c) (i) Armature is a coil which carries current and rotates in magnetic field.
(ii) Brushes are used to make contact with rotating spilt-rings so as to supply current to the armature.
(iii) Split ring is used for reversing the direction of flow of current through.