Objective Questions Short notes Objective questions (Answers are given below) With same maximum voltage between conductors,the ratio of copper volumes in 3-phase, 3-wire system and 1-phase, 2-wire system is(a) 4/3 (b) 3/4(c) 5/3 (d) 3/5 The volume of copper required for an a.c. transmissionline is inversely proportional to(a) current (b) voltage(c) power factor (d) both … Read more
Objective Questions Short notes Objective questions (Answers are given below) If in a d.c. 2-wire feeder, drop per feederconductor is 2%, transmission efficiency ofthe feeder is ……………………… percent.(a) 98 (b) 94(c) 96 (d) 99 Transmitted power remaining the same, ifsupply voltage of a dc 2-wire feeder isincreased by 100 percent, saving in copperis …………………….. percent.(a) … Read more
MCQ ON SPECIAL MACHINES Objective Questions Short notes Objective questions (Answers are given below) A single-stack, 4-phase, 6-pole VR steppermotor will have a step angle of(a) 15º(b) 30º(c) 45º(d) 90º In a three-stack 12/8-pole VR motor, the rotorpole pitch is(a) 15º(b) 30º(c) 45º(d) 60º A three-stack VR stepper motor has a step angleof 10º. What … Read more
SYNCHRONOUS MOTOR :A synchronous motor is one in which the rotor normally rotates at the same speed as the revolving field in the machine. The stator is similar to that of an induction machine consisting of a cylindrical iron frame with windings, usually three-phase, located in slots around the inner periphery. Objective Questions Short notes Objective questions (Answers are given … Read more
MCQ ON ALTERNATORS Objective Questions Short notes Objective questions (Answers are given below) The frequency of voltage generated by an alternatorhaving 4-poles and rotating at 1800 r.p.m.is …….hertz.(a) 60 (b) 7200(c) 120 (d) 450. A 50-Hz alternator will run at the greatestpossible speed if it is wound for ……. poles.(a) 8 (b) 6(c) 4 (d) … Read more