Question is ⇒ To limit the operating temperature an electrical machine should have proper, Options are ⇒ (A) voltage rating, (B) current rating, (C) power factor, (D) speed, (E) , Leave your comments or Download question paper.

Question is ⇒ To limit the operating temperature an electrical machine should have proper, Options are ⇒ (A) voltage rating, (B) current rating, (C) power factor, (D) speed, (E) , Leave your comments or Download question paper. Previous question Next question


Q1.	To limit the operating temperature an electrical machine should have proper
A.	voltage rating [Wrong Answer]
B.	current rating [Correct Answer]
C.	power factor [Wrong Answer]
D.	speed [Wrong Answer]
View Answer 9 -1 Explanation:- Answer : B Discuss it below : !! OOPS Login [Click here] is required to post your answer/result Help other students, write article, leave your comments

Previous question Next question

Also Read Similar Questions Below :

⇒ A synchronous motor is running with normal excitation. When the load is increased, the armature current drawn by it increases because
speed of the motor is reduced
power factor is decreased
Eb (back e.m.f.) becomes less than V (applied voltage)
Er (net resultant voltage) in armature is increased

⇒ The induced e.m.f. in a synchronous motor working on leading power factor will be
more than the supply voltage
less than the supply voltage
equal to the supply voltage

⇒ In a synchronous machine in case the axis of field flux is in line with the armature flux, then
the machine is working as synchronous generator
the machine is working as synchronous motor
the machine will vibrate violently
none of the above

⇒ A synchronous motor can develop synchronous torque
when under loaded
while over-excited
only at synchronous speed
below or above synchronous speed

⇒ In a synchronous motor, the magnitude of stator back e.m.f. Eb depends on
load on the motor
d.c. excitation only
both the speed and rotor flux
none of the above

⇒ As the load is applied to a synchronous motor, the motor takes more armature current because
the increased load has to take more current
the rotor by shifting its phase backward causes motor to take more current
the back e.m.f. decreases causing ah increase in motor current
the rotor strengthens the rotating field casuing more motor current

⇒ A synchronous motor installed at the receiving end substation operates with such an excitation that it takes power at lagging power factor. Now if the applied voltage of the synchronous motor goes down, the power factor of the synchronous motor will
remain same
go down
improve
none of the above

⇒ The back e.m.f. of a synchronous motor depends on
speed
load
load angle
all of the above

⇒ Synchronous motors are
not-self starting
self-starting
essentially self-starting
none of the above

⇒ The size of a synchronous motor decreases with the increase in
flux density
horse power rating
speed
all of the above

⇒ An over-excited synchronous motor takes
leading current
lagging current
both (a) and (b)
none of the above

⇒ To limit the operating temperature an electrical machine should have proper
voltage rating
current rating
power factor
speed

⇒ The maximum torque which a synchronous motor will develop at rest for any angular position of the rotor, at rated stator supply voltage and frequency, is known as
locked-rotor torque
synchronous torque
pull up torque
reluctance torque

⇒ While starting a synchronous motor by induction motor action, field winding is usually
connected to D.C. supply
short-circuited by low resistance
kept open-circuited
none of the above

⇒ When a 3-phase synchionous generator is supplying a zero power factor lagging load, the armature field affects the main field in the following way
augments it directly
directly opposes it
cross-magnetises it
none of the above

⇒ A synchronous motor develops maximum power when load angle is
45°
60°
90°
120°

⇒ When V is the supply voltage and R is the rotor resistance per phase, the mechanical power developed by the synchronous motor will be proportional to

V²

R²