This set of DC Machines Questions and Answers for Campus interviews focuses on “DC Motor Control Through Choppers”. 1. Which of the following method is adopted for controlling a DC motor? a) Resistance control b) Motor-generator set c) Inverter Rectifier d) DC chopper 2. Which of the following method is employed when regenerative braking is … Read more
This set of DC Machines Multiple Choice Questions & Answers (MCQs) focuses on “DC Motor Control Through Converters”. 1. Half wave converters are used for controlling DC motor of ________________ a) Below 400 W b) 400 W – 4000W c) More than 4000W d) Anywhere 2. How many thyristors does we need in half wave … Read more
This set of DC Machines Multiple Choice Questions & Answers (MCQs) focuses on “BLDC Motors”. 1. In BLDC motor field winding is kept on _______________ a) Stator b) Rotor c) Can be placed anywhere d) Absent 2. By electronic circuitry BLDC can be controlled for both constant and variable torque operation. a) True b) False … Read more
This set of DC Machines Multiple Choice Questions & Answers (MCQs) focuses on “Hopkinson’s Test”. 1. Hopkinson’s test of D.C. machines is conducted at _______________ a) No-load b) Part load c) Full-load d) Overload 2. Hopkinson’s test requires ____________ a) One DC machine on which test is carried out b) Two different DC machines c) … Read more
This set of DC Machines Multiple Choice Questions & Answers (MCQs) focuses on “Swinburne’s Test”. 1.Swinburne’s test can be carried out on all DC motors. a) True b) False 2. Which of the following test will be suitable for testing two similar DC series motors of large capacity? a) Swinburne’s test b) Hopkinson’s test c) … Read more
This set of DC Machines Questions and Answers for Entrance exams focuses on “Efficiency of DC Machine – 2”. 1. The condition for maximum efficiency for a DC generator is __________ a) Eddy current losses = stray losses b) Hysteresis losses = eddy current losses c) Copper losses = 0 d) Variable losses = constant … Read more
This set of DC Machines Multiple Choice Questions & Answers (MCQs) focuses on “Efficiency of DC Machine- 1”. 1. The efficiency of the DC motor at maximum power will be ___________________ a) 100% b) Around 90% c) Anywhere between 75% and 90% d) Less than 50% 2. The hysteresis loss in a DC machine least … Read more
This set of DC Machines Question Bank focuses on “Braking of DC Motors – 2”. 1. Regenerative braking is used when duty cycle ____________ a) Requires braking of machine b) Requires accelerating of machine c) Requires constancy of machine d) Cannot comment on duty cycle 2. Regeneration is not easily possible for ____________ a) DC … Read more
This set of DC Machines Multiple Choice Questions & Answers (MCQs) focuses on “Braking of DC Motors – 1”. 1. Which of the following is the best braking method? a) Friction b) Electromechanical action c) Eddy-currents d) Electric braking 2. DC motor is still widely used in tractions due to its excellent braking properties. a) … Read more
This set of DC Machines Multiple Choice Questions & Answers (MCQs) focuses on “Ward Leonard Speed Control Method”. 1. Ward Leonard method is ___________ a) Armature control method b) Field control method c) Combination of armature control method and field control method d) Totally different from armature and field control method 2. Which of the … Read more
