Why doesn't coil in an Ac generator not get deflected in accordance to the flemming's left hand rule when current starts to flow through it Why doesn't coil in an Ac generator not get deflected in accordance to the Flemming's  left hand rule when current starts to flow through it.
When the coil is rotated by some mechanical means, electric current is induced in the coil, and current starts to flow through it. Now if we apply Flemming's left hand rule the direction of coil rotation is different than what is obtained when Right hand rule is used
 A: Fleming's rules at www.electricaltechnology.org show and tell the difference between the two.  The left-hand rule is for motors: the current causes the wire to move.  The right-hand rule is for generators: the motion of the wire causes the current.  These rules are a quick way to relate motion, current, and field directions.  They are not the basis of electric force on a wire (motor) and magnetic induction (generator).
A: To make a generator work a force/torque is applied to the coil and a voltage is induced.
If the coil is part of a complete electrical circuit the induced voltage results in an induced current in the circuit.
The direction of the voltage/current can be deduced by using Fleming's right had rule.
You are quite right that the current carrying coil in a magnetic field experiences a force/torque whose direction can be deduced using Fleming's left hand rule, and that force/torque is in the opposite direction to the force/torque applied to rotate the coil.
Here you have Lenz's law in action with the induced current in such a direction FRHR) as to oppose (FLHR) the motion producing it.
