During hunting of synchronous motor

An induction motor having full load torque of $$60$$ $$Nm$$ when delta-connected develops a starting torque of $$120$$ $$N$$-$$m.$$ For the same simply voltage, if the motor is changed to star-connection, the starting torque developed will be

When the supply voltage to an induction motor is reduced by $$10\% $$, the maximum torque will decrease by approximately

In Figure. The characteristic that corresponds to the variation of synchronous reactance of synchronous motor with field current is