Rajasthan Technical Education Second Year Paper 2016 Electrical Engineering and Measurements

A D.C. series motor must not be run at no load because
(a) It will draw a dangerously large current
(b) It will run at dangerously high speed
(c) It will run at slow speed
(d) It will stall

The armature torque of the DC shunt motor is proportional to
(a) Armature current only
(b) Field flux only
(c) Armature current and flux both
(d) None of the above

The induced emf in the armature conductors of a d.c motor is
(a) Trapezoidal
(b) Rectangular
(c) Square
(d) Sinusoidal

For the requirment of high starting torque, the motor used is
(a) Induction motor
(b) DC shunt motor
(c) Synchronous motor
(d) DC series motor

The short circuit test in transformer is used to determine
(a) The iron loss at any load
(b) The copper loss at any load or at full load
(c) The hystersis loss
(d) The eddy current loss

Which of the following electrical machines has the highest efficiency ?
(a) DC shunt motor
(b) Transformer
(c) Induction motor
(d) Synchronous motor

A 4 pole, 50 Hz, 400 V induction motors runs at a speed of 1440 rpm then slip is
(a) 4%
(b) 4.2%
(c) 15%
(d) 15.2%

Which of the following types of motor is NOT a self starting ?
(a) Synchronous motor
(b) DC series motor
(c) 3 phase induction motor
(d) DC shunt motor

For synchronous motor ‘V’curve draw between
(a) Armature current and field current
(b) Power factor and field current
(c) Armature current and torque
(d) Torque and field current

An induction motor can run at synchronous speed
(a) On no load
(b) On full load
(c) Never
(d) If number of poles are very large

A 3-phase, 400 V supply is connected to a 3-phase star connected balanced load. The line current is 10A, then the per phase impedance of the load is
(a) 13.33 Ohms
(b) 40 Ohms
(c) 69.28 Ohms
(d) 23.09 Ohms