Q.1
##### Which of the following DC motor has the poorest speed control?
• a) Differentially compounded motor
• b) Cumulatively compounded motor
• c) Shunt motor
• d) Series motor
Q.2
##### In variable speed motor ____________
• a) Stronger commutating field is needed at low speed than at high speed
• b) Weaker commutating field is needed at low speed than at high speed
• c) Same commutating field is needed at low speed and at high speed
• d) Cannot be determined
Q.3
• a) 12.36%
• b) 14.28%
• c) 16.77%
• d) 18.84%
Q.4
##### Which of the following is not the method of speed control in DC series motor?
• a) Diverter
• b) Tapped-field control
• c) Variable resistance in series with armature
• d) Series- parallel control
Q.5
• a) True
• b) False
Q.6
• a) 2:1
• b) 4:1
• c) 6:1
• d) 8:1
Q.7
##### In diverter resistor field control method of DC series motor, variable resistor is added ________
• a) In parallel with field
• b) In series with field
• c) In parallel with armature
• d) In parallel with load
Q.8
##### Why it is advisable to use inductively wound diverter resistor?
• a) To make speed control on more range
• b) For long-life of machine
• c) Cost efficient
• d) To avoid oscillations in speed
Q.9
##### For higher diverter resistance, speed-torque characteristic will lie ____________
• a) Above speed-torque characteristic of lower resistance
• b) Below speed-torque characteristic of lower resistance
• c) On the speed-torque characteristic of lower resistance
• d) Cannot say
Q.10
##### In tapped field control method ____________
• a) A variable resistor is connected in parallel
• b) A variable resistor is connected in series
• c) Field winding is made with more out pins
• d) Another field winding is added with the previous one
Q.11
##### Which of the following method will not give many speed values for a DC series motor?
• a) Diverter
• b) Series-parallel
• c) Field tapped
• d) All field control methods will give many speed values
Q.12
##### In series-parallel speed control method ______________
• a) Speed given by parallel connection is more
• b) Speed given by series connection is more
• c) Both speeds can be equal
• d) Will depend on other parameters
Q.13
##### Where diverters are used?
• a) In shunt motors
• b) In series motors
• c) In both motors
• d) All other motors except shunt and series motors
Q.14
##### What will happen to the speed of a series motor if the temperature of armature resistance is increased?
• a) Not change
• b) Decreases
• c) Increases
• d) Cannot be determined