The probes of a non $$-$$ isolated, two-channel oscilloscope are clipped to points $$A, B, $$ and $$C$$ in the circuit of the adjacent fig. $${V_{in}}$$ is a square wave of a suitable low frequency. The display on $$c{h_1}$$ and $$c{h_2}$$ are as shown on the right. Then the ''signal'' and ''Ground'' probes $${S_1},\,\,{G_1}$$ and $${S_2},\,\,{G_2}$$ of $$c{h_1}$$ and $$c{h_2}$$ respectively are connected to points.

A three phase squirrel cage induction motor has a starting current of seven times the full load current and full load slip of $$5\% $$

If a starting torque of $$0.5$$ per unit is required then the per unit starting current should be

A $$100$$ $$kVA$$, $$415V,$$ star connected synchronous machine generates rated open circuit voltage $$415V$$ at a field current of $$15A.$$ The short circuit armature current at a field current of $$10A$$ is equal to the rated armature current. The per unit saturated synchronous reactance is

A $$3$$ phase, $$3$$ stack, variable reluctance stepper motor has $$20$$ poles on each rotor and stator stack. The step angle of this stepper motor is