a) “CONT” on a motor nameplate indicates that the motor can put out ____________
ID: 2291770 • Letter: A
Question
a) “CONT” on a motor nameplate indicates that the motor can put out _____________ power continuously.
b) ______________ DC motors have electronic commutators.
c) Stepper motors are used when precise, repeatable shaft _____________ is required.
d) Single-phase induction motors usually have a(n) ______________ winding for starting the motor.
e) Which one of these cannot be a synchronous speed? (3600, 2400, 1800, 1200, 600) rpm
f) There are five kinds of power losses in AC motors. Name them:
1. _________________________
2. _________________________
3. _________________________
4. _________________________
5. _________________________
g) If the starting torque of the load is greater than the starting torque of the motor, the motor will ____________.
h) Most motors can supply several times their rated power for short periods of time. Ultimately, the motor _________________________ limits the power output.
i) Three-phase synchronous motors have ______________________ starting torque.
j) If an induction motor has no _______________________, its speed will approach the synchronous speed.
k) If the field is reduced on an unloaded shunt-connected motor, the motor will
(speed up, slow down, remain at the same speed).
l) A wheel on a vehicle has a diameter of 750 cm and rotates at 200 rpm. The speed of the vehicle is ____________ m/s.
m) Typical industrial motor efficiency is 85-95% at _______________ load.
n) A crank handle is 50 cm long. You push down on the crank handle with a force of 15 N. The torque on the crank is ______________ N-m.
o) Back EMF opposes the applied ________________.
p) A permanent magnet motor has the same torque-speed curve as a(n) ______________ motor.
q) What kind of motor is sometimes used without a load for power factor correction? _______________ motor.
r) What kind of motor runs at a constant speed regardless of the load? _________________motor.
s) The armature winding is on the (rotor, stator, either rotor or stator).
t) What do you call the part of a motor that rotates? ______________
u) The most common motor in the world is an induction motor with a ______________ rotor.
v) What do you call the part of a motor that does not rotate? ____________________
w) Motor brushes are usually made out of what material? ______________
x) What do you call a motor that can run on both AC and DC? ___________________________
y) EMF stands for _____________________________
z) Back EMF is proportional to the field strength and the ______________ of rotation.
Explanation / Answer
Answer is given in between blank spaces.
a) “CONT” on a motor nameplate indicates that the motor can put out __constant___ power continuously.
b) ____Brushless_____ DC motors have electronic commutators.
c) Stepper motors are used when precise, repeatable shaft ___toque output_____ is required.
d) Single-phase induction motors usually have a(n) ___Auxilliary __ winding for starting the motor.
e) Which one of these cannot be a synchronous speed? (3600, 2400, 1800, 1200, 600) rpm
Synchonous speed = 120*f/P Here f= frequency 60Hz and P= no. of poles in even numbers
Hence 2400 can't be synchonous speed
f) There are five kinds of power losses in AC motors. Name them:
1. _Magnettic leakage loss________________________
2. _Hysteresis loss________________________
3. __Copper loss or I^2*R loss_______________________
4. __Mechanical Loss_______________________
5. ___Windage and friction loss______________________
g) If the starting torque of the load is greater than the starting torque of the motor, the motor will __not start __________.
h) Most motors can supply several times their rated power for short periods of time. Ultimately, the motor _________________________ limits the power output.
i) Three-phase synchronous motors have _____high _________________ starting torque.
j) If an induction motor has no _________load______________, its speed will approach the synchronous speed.
k) If the field is reduced on an unloaded shunt-connected motor, the motor will
(speed up, slow down, remain at the same speed). slow down
l) A wheel on a vehicle has a diameter of 750 cm and rotates at 200 rpm. The speed of the vehicle is ____12.5________ m/s.
speed = angular speed * radius
m) Typical industrial motor efficiency is 85-95% at _____full__________ load.
n) A crank handle is 50 cm long. You push down on the crank handle with a force of 15 N. The torque on the crank is ________7.5______ N-m.
Torque = force * length
o) Back EMF opposes the applied ________field current________.
p) A permanent magnet motor has the same torque-speed curve as a(n) ____synchronous__________ motor.
q) What kind of motor is sometimes used without a load for power factor correction? _____synchonous__________ motor.
r) What kind of motor runs at a constant speed regardless of the load? _________sychronous________motor.
s) The armature winding is on the (rotor, stator, either rotor or stator).
either rotor or stator depending upon motor size and use
t) What do you call the part of a motor that rotates? ___rotor___________
u) The most common motor in the world is an induction motor with a ____squirrel cage__________ rotor.
v) What do you call the part of a motor that does not rotate? ____________stator________
w) Motor brushes are usually made out of what material? ______graphite________
x) What do you call a motor that can run on both AC and DC? ________universal motor___________________
y) EMF stands for _______________electro motive force______________
z) Back EMF is proportional to the field strength and the ______________ of rotation.
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.