1
GATE EE 2023
MCQ (Single Correct Answer)
+1
-0.33

The four stator conductors (A, A', B and B') of a rotating machine are carrying DC currents of the same value, the directions of which are shown in the figure (i). The rotor coils $$a$$-$$a'$$ and $$b$$-$$b'$$ are formed by connecting the back ends of conductors '$$a$$' and '$$a'$$' and '$$b$$' and '$$b'$$', respectively, as shown in figure (ii). The e.m.f. induced in coil $$a$$-$$a'$$ and coil $$b$$-$$b'$$ are denoted by $${E_{a - a'}}$$ and $${E_{b - b'}}$$, respectively. If the rotor is rotated at uniform angular speed $$\omega$$ rad/s in the clockwise direction then which of the following correctly describes the $${E_{a - a'}}$$ and $${E_{b - b'}}$$?

GATE EE 2023 Electrical Machines - D.C Machines Question 3 English

A
$${E_{a - a'}}$$ and $${E_{b - b'}}$$ have finite magnitudes and are in the same phase
B
$${E_{a - a'}}$$ and $${E_{b - b'}}$$ have finite magnitudes with $${E_{b - b'}}$$ leading $${E_{a - a'}}$$
C
$${E_{a - a'}}$$ and $${E_{b - b'}}$$ have finite magnitudes with $${E_{a - a'}}$$ leading $${E_{b - b'}}$$
D
$${E_{a - a'}}$$ = $${E_{b - b'}}$$ = 0
2
GATE EE 2023
Numerical
+1
-0

A separately excited DC motor rated 400 V, 15 A, 1500 RPM drives a constant torque load at rated speed operating from 400 V DC supply drawing rated current. The armature resistance is 1.2 $$\Omega$$. If the supply voltage drops by 10% with field current unaltered then the resultant speed of the motor in RPM is ____________ (Round off to the nearest integer).

Your input ____
3
GATE EE 2018
Numerical
+1
-0
A separately excited dc motor has an armature resistance R$$a$$ = 0.05⁡Ω. The field excitation is kept constant. At an armature voltage of 100 V, the motor produces a torque of 500 Nm at zero speed. Neglecting all mechanical losses, the no-load speed of the motor (in radian/s) for an armature voltage of 150 V is _____ (up to 2 decimal places).
Your input ____
4
GATE EE 2016 Set 1
MCQ (Single Correct Answer)
+1
-0.3
A 4-pole, lap-connected, separately excited dc motor is drawing a steady current of 40 A while running at 600 rpm. A good approximation for the waveshape of the current in armature conductor of the motor is given by
A
GATE EE 2016 Set 1 Electrical Machines - D.C Machines Question 55 English Option 1
B
GATE EE 2016 Set 1 Electrical Machines - D.C Machines Question 55 English Option 2
C
GATE EE 2016 Set 1 Electrical Machines - D.C Machines Question 55 English Option 3
D
GATE EE 2016 Set 1 Electrical Machines - D.C Machines Question 55 English Option 4
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