GATE EE 2003 | Induction Machines Question 64 | Electrical Machines

GATE EE 2003

MCQ (Single Correct Answer)

-0.3

No-load test on a 3-phase induction motor was conducted at different supply voltages and a plot of input power versus voltage was drawn. This curve was extrapolated to intersect the y-axis. This intersection point yields

Core loss

Stator copper loss

Stray load loss

Friction and windage loss

GATE EE 2003

MCQ (Single Correct Answer)

-0.3

Group I lists different applications and Group II lists the motors for these applications. Match the application with the most suitable motor and choose the right combination among the choices given there after:

Group I
P. Food mixer
Q. Cassette tape recorder
R. Domestic water pump
S. Escalator

Group II
1. Permanent magnet dc motor
2. Single phase induction motor
3. Universal motor
4. Three phase induction motor
5. DC series motor
6. Stepper motor

$$\begin{array}{l}P\;\;\;Q\;\;\;R\;\;\;S\\3\;\;\;\;6\;\;\;\;4\;\;\;\;5\\\end{array}$$

$$\begin{array}{l}P\;\;\;Q\;\;\;R\;\;\;S\\1\;\;\;\;3\;\;\;\;2\;\;\;\;4\\\end{array}$$

$$\begin{array}{l}P\;\;\;Q\;\;\;R\;\;\;S\\3\;\;\;\;1\;\;\;\;2\;\;\;\;4\\\end{array}$$

$$\begin{array}{l}P\;\;\;Q\;\;\;R\;\;\;S\\3\;\;\;\;2\;\;\;\;1\;\;\;\;4\\\end{array}$$

GATE EE 2002

MCQ (Single Correct Answer)

-0.3

If a 400 V, 50 Hz, star connected, 3 phase squirrel cage induction motor is operated from a 400 V, 75 Hz supply, the torque that the motor can now provide while drawing rated current from the supply?

reduces

increases

remains the same

increase or reduces depending upon the rotor resistance

GATE EE 1999

MCQ (Single Correct Answer)

-0.3

The following starting method for an induction motor is inferior view of the poor starting torque per ampere of the line current drawn:

Direct line starting

Auto transformer method of starting

Series inductor method of starting

Star-Delta method of starting