1. What is the primary advantage of using a DC shunt motor?
a) High starting torque
b) Constant speed under varying loads
c) Simple construction
d) Low maintenance
Answer: b) Constant speed under varying loads
2. In a DC shunt motor, the field winding is connected in __________ with the armature winding.
a) Series
b) Parallel
c) Series-parallel
d) None of the above
Answer: b) Parallel
3. Which of the following statements is true for a DC shunt motor under no-load conditions?
a) The speed is maximum
b) The speed is minimum
c) The speed is zero
d) The speed is constant
Answer: d) The speed is constant
4. What happens to the speed of a DC shunt motor as the load torque increases?
a) Speed increases
b) Speed decreases
c) Speed remains constant
d) Speed becomes zero
Answer: c) Speed remains constant
5. The starting torque of a DC shunt motor is __________ compared to other types of DC motors.
a) Higher
b) Lower
c) Same
d) Unpredictable
Answer: b) Lower
6. The speed-torque characteristic of a DC shunt motor is ___________.
a) Hyperbolic
b) Linear
c) Parabolic
d) Exponential
Answer: b) Linear
7. Which of the following statements is true for a DC shunt motor operating below its rated voltage?
a) The speed decreases
b) The speed increases
c) The speed remains constant
d) The motor stalls
Answer: a) The speed decreases
8. A DC shunt motor is not suitable for applications that require ___________.
a) High starting torque
b) Variable speed control
c) Low current consumption
d) Long operational life
Answer: a) High starting torque
9. What is the typical application of a DC shunt motor?
a) Ceiling fan
b) Elevator
c) Electric vehicle
d) Mixer grinder
Answer: b) Elevator
10. What protects a DC shunt motor from excessive current in case of a sudden load reduction?
a) Capacitor
b) Rheostat
c) Centrifugal switch
d) Circuit breaker
Answer: d) Circuit breaker
11. Which component is commonly used in a DC shunt motor to control its speed?
a) Diode
b) Capacitor
c) Rheostat
d) Transformer
Answer: c) Rheostat
12. What happens if the field winding of a DC shunt motor is disconnected while it’s running?
a) The motor stops immediately
b) The motor runs at full speed
c) The motor reverses direction
d) The motor continues to run at the same speed
Answer: b) The motor runs at full speed
13. The torque-speed characteristic of a DC shunt motor shows a __________ relationship.
a) Linear
b) Hyperbolic
c) Parabolic
d) Inverse
Answer: a) Linear
14. Which component is responsible for the commutation process in a DC shunt motor?
a) Armature
b) Brushes
c) Commutator
d) Field coil
Answer: b) Brushes
15. A DC shunt motor is not recommended for applications that require ___________.
a) Variable speed control
b) Rapid acceleration
c) Minimal maintenance
d) Smooth and precise control
Answer: b) Rapid acceleration
16. What is the speed regulation of a DC shunt motor with increasing load?
a) Positive
b) Negative
c) Zero
d) Unpredictable
Answer: b) Negative
17. In a DC shunt motor, the armature current is controlled by ___________.
a) Supply voltage
b) Field current
c) Armature resistance
d) Commutator
Answer: c) Armature resistance
18. The efficiency of a DC shunt motor is highest at ___________.
a) No-load
b) Full load
c) Half-load
d) Overload
Answer: b) Full load
19. Which type of DC motor exhibits relatively constant speed from no-load to full-load?
a) Series
b) Shunt
c) Compound
d) Separately excited
Answer: b) Shunt
20. What protects a DC shunt motor from armature winding damage due to excessive current?
a) Thermal overload relay
b) Voltage regulator
c) Fuse
d) Flywheel
Answer: a) Thermal overload relay
21. The back EMF (electromotive force) in a DC shunt motor is directly proportional to ___________.
a) Armature current
b) Armature resistance
c) Field current
d) Supply voltage
Answer: d) Supply voltage
22. The armature windings in a DC shunt motor are usually made of ___________.
a) Copper
b) Aluminum
c) Iron
d) Silver
Answer: a) Copper
23. What type of load is most suitable for a DC shunt motor?
a) Constant torque
b) Constant speed
c) Variable torque
d) No-load
Answer: b) Constant speed
24. In a DC shunt motor, reversing the direction of current through the armature will ___________.
a) Increase speed
b) Decrease speed
c) Reverse the direction of rotation
d) Have no effect on speed or rotation
Answer: c) Reverse the direction of rotation
25. What is the most common cause of armature failure in a DC shunt motor?
a) Overheating
b) Excessive vibration
c) Short circuit
d) Open circuit
Answer: c) Short circuit
26. The torque produced by a DC shunt motor is proportional to ___________.
a) Speed
b) Voltage
c) Current
d) Resistance
Answer: c) Current
27. What happens if the field winding in a DC shunt motor becomes open (breaks)?
a) The motor will not start
b) The motor will run at maximum speed
c) The motor will stop running
d) The motor will draw excessive current
Answer: b) The motor will run at maximum speed
28. The direction of rotation of a DC shunt motor can be reversed by ___________.
a) Changing the field winding polarity
b) Changing the armature winding polarity
c) Changing the direction of the armature current
d) Changing the direction of field’s current
Answer: b) Changing the armature winding polarity
29. In a DC shunt motor, the speed can be controlled by varying ___________.
a) Armature voltage
b) Field voltage
c) Armature current
d) Field current
Answer: d) Field current
30. What happens to the torque produced by a DC shunt motor as the load torque increases?
a) Torque increases
b) Torque decreases
c) Torque remains constant
d) Torque becomes zero
Answer: c) Torque remains constant