Electrical Machines
Induction Machines
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Synchronous Machines
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1
GATE EE 2007
MCQ (Single Correct Answer)
+2
-0.6
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
$$4.65$$
B
$$3.75$$
C
$$3.16$$
D
$$2.13$$
2
GATE EE 2007
MCQ (Single Correct Answer)
+2
-0.6
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 star-delta starter is used to start this induction motor, the per unit staring torque will be

A
$$0.607$$
B
$$0.816$$
C
$$1.225$$
D
$$1.616$$
3
GATE EE 2007
MCQ (Single Correct Answer)
+2
-0.6
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 an auto-transformer is used for reduced voltage starting to provide $$1.5$$ per unit starting torque, the auto-transformer ratio $$\left( \% \right)$$ should be

A
$$57.77\% $$
B
$$72.56\% $$
C
$$78.25\% $$
D
$$81.33\% $$
4
GATE EE 2006
MCQ (Single Correct Answer)
+2
-0.6
A $$3$$ phase, $$4$$ pole, $$400$$ $$V,$$ $$50$$ $$Hz,$$ star connected induction motor has following circuit parameters $${r_1} = 1.0\Omega ,\,{r_2} = 0.5\Omega ,$$ $${\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {x_1} = x{'_2} = 1.2\Omega ,{\mkern 1mu} {x_m} = 35\Omega $$
The starting torque when the motor is started direct-on-line is (use approximate equivalent circuit model)
A
$$63.6$$ $$Nm$$
B
$$74.3$$ $$Nm$$
C
$$190.8$$ $$Nm$$
D
$$222.9$$ $$Nm$$
GATE EE Subjects
Electromagnetic Fields
Signals and Systems
Engineering Mathematics
General Aptitude
Power Electronics
Power System Analysis
Analog Electronics
Control Systems
Digital Electronics
Electrical Machines
Electric Circuits
Electrical and Electronics Measurement