This set of Electric Drives Puzzles focuses on “DC Motors – Direct Control of Armature-Terminal Voltage” 1. Calculate the frequency of the waveform x(t)=45sin(40πt+5π). a) 24 Hz b) 27 Hz c) 23 Hz d) 20 Hz 2. The generated e.m.f from 16-pole armature having 57 turns driven at 78 rev/sec having flux per pole as … Read more
This set of Electric Drives Multiple Choice Questions & Answers (MCQs) focuses on “DC Motors – Application of Modified Characteristics”. 1. Calculate the time period of the waveform y(t)=74cos(81πt+π). a) .024 sec b) .027 sec c) .023 sec d) .025 sec 2. The generated e.m.f from 42-pole armature having 74 turns driven at 64 rev/sec … Read more
This set of Electric Drives Interview Questions and Answers for freshers focuses on “Modified Speed Torque Characteristics of DC Series Motors”. 1. Turn-on and turn-off times of transistor depend on _________ a) Static Characteristic b) Junction Capacitance c) Current Gain d) Voltage Gain 2. The generated e.m.f from 45-pole armature having 400 turns driven at … Read more
This set of Electric Drives Multiple Choice Questions & Answers (MCQs) focuses on “Modified Speed Torque Characteristics of DC Shunt Motors”. 1. In DC chopper, the waveform for input and output voltages is respectively __________ a) Discontinuous and Continuous b) Continuous and Discontinuous c) Both continuous d) Both discontinuous 2. A chopper behaves as a … Read more
This set of Electric Drives Multiple Choice Questions & Answers (MCQs) focuses on “DC Motors – Basic Characteristics”. 1. Calculate the terminal voltage of Permanent Magnet DC motor having a resistance of 2 Ω and a full load current of 5 A with 20 V back e.m.f. a) 30 V b) 25 V c) 20 … Read more
This set of Electric Drives Multiple Choice Questions & Answers (MCQs) focuses on “DC Motors Characteristics – Basic Relations”. 1. Swinburne’s test can be conducted on ___________ a) Series motor b) Shunt motor c) Compound motor d) Shunt and compound motor 2. The generated e.m.f from 20-pole armature having 800 conductors driven at 30 rev/sec … Read more
This set of Tricky Electric Drives Questions and Answers focuses on “Dynamics – Transient Stability of an Electric Drive”. 1. What is the formula for the active power in the cylindrical rotor synchronous machine? (Eb represents armature emf, Vt represents terminal voltage, δ represents rotor angle, X represents reactance) a) Eb×Vt×sinδ÷X b) Eb×Vt2×sinδ÷X c) Eb2×Vt×sinδ÷X … Read more
This set of Electric Drives Multiple Choice Questions & Answers (MCQs) focuses on “Dynamics – Steady State Stability of Electric Drive”. 1. A 4-pole lap wound generator with 720 armature conductors and a flux per pole of .003 Wb has an armature current of 50 A. The developed torque is _________ a) 17.25 N-m b) … Read more
This set of Electric Drives Questions and Answers for Freshers focuses on “Dynamics – Moment of Inertia Determination”. 1. What is the formula for the moment of inertia? (m – a mass of the body, r – distance from the axis of the rotation) a) ∑miri2 b) ∑miri c) ∑miri4 d) ∑miri3 2. The generated … Read more
This set of Electric Drives Multiple Choice Questions & Answers (MCQs) focuses on “Dynamics of Motor-Load Combination”. 1. The axis along which no emf is produced in the armature conductors is called as ____________ a) Geometrical Neutral Axis (GNA) b) Magnetic Neutral Axis (MNA) c) Axis of rotation d) Axis of revolution 2. The generated … Read more
