Electrical Machines Test Questions
Electrical Machines Test Questions, this topic has 410 mcqs, It takes five to ten minutes to complete this free Electrical Machines Test Questions test. You will see 4 or 5 option of each question. You must choose / think only one option and then press on answer key for check right answer. Practice "Electrical Machines Test Questions" MCQs and share with your friends, brothers, sisters.
Electrical Machines Test Questions (Total Quiz: 410)
MCQ: Iron losses are considered to be the constant losses. It depends on
- Voltage
- Frequency
- Both (a) and (b)
- None of these
C
MCQ: Copper losses in a rotating machine are
- Variable losses
- Constant losses
- Both (a) or (b)
- None of these
A
MCQ: Stray losses are the losses which vary with the load but their relationship with load current cannot be identified. Stay losses is maximum in
- Synchronous machines
- D.C. machines
- Induction machines
- Equal in all types of machines
B
MCQ: The brush contact losses in a d.c. Machine is
- Inversely proportional to the square of current
- Directly proportional to the square of current
- Inversely proportional to the current
- Directly proportional to the current
D
MCQ: Electrical power output in a d.c. generator is equal to
- Electrical power developed in armature – copper losses
- Mechanical power input – iron and friction losses
- Electrical power developed in armature – iron and copper losses
- Mechanical power input – iron and friction losses – copper losses
D
MCQ: Mechanical power developed in armature of a d.c. motor is given by
- Electrical power input to motor – copper losses
- Motor output + iron and friction losses
- Both (a) & (b)
- None of these
C
MCQ: Out of electrical, mechanical and magnetic losses, the losses which is minimum is
- All are equal
- Electrical losses
- Magnetic losses
- Mechanical losses
D
MCQ: The hysteresis motor are mainly used in tape recorders because
- Of its extremely steady torque
- Constant speed
- Reduced initial current
- None of these
A
MCQ: A 120 V shunt generator running at 850 rpm has its armature and shunt field resistance of 0.15 ohm and 50 ohm respectively. It supplies 200 lamps each rated at 60 W, 100 V. The friction and windage and core loss of the machine is 400 W. its armature copper loss on full load and shunt field loss is
- 2156.7 W, 200 W
- 2232.6 W, 200 W
- 2156.7 W, 240 W
- 2232.6 W, 240 W
B
MCQ: A d.c. shunt generator delivers 190 A at a terminal voltage of 220 V. The copper losses and stray losses are 2000 W and 1000 W respectively. The efficiency of the generator is
- 91.35 %
- 92.60 %
- 93.30 %
- 94.23 %
C