Name and state the rule to find the direction of :
(a) current induced in a coil due to its rotation in a magnetic field.
(b) force experienced by a current-carrying straight conductor placed in a magnetic field which is perpendicular to it.
(i) Fleming's right hand rule : The direction of induced current in a straight conductor is given by Fleming’s right hand rule. It states that if we stretch the thumb, forefinger and the middle finger of right hand at right angles to one another in such a way that the forefinger points in the direction of magnetic field. Then, thumb gives the direction of motion of conductor (force), forefinger indicates direction of magnetic field and the middle finger points the direction of induced current.
(ii) Fleming's left hand rule : Whenever a current carrying conductor is placed in a magnetic field, the conductor experiences a force. According to Flemings left hand rule if the thumb, forefinger and middle finger of left hand are stretched perpendicular to each other as shown the figure and if fore finger represents the direction of magnetic field, the middle finger represents the direction of current, and then the thumb represents the direction of force.