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Electrical machine design
| 1-Dont try to cram or spend more time here just read it fast and cover syllabus then practice MCQ's cheptor of same topic to check your progress. . |
| 2-Wrong options are also given but dont concentrate there, Right answer is in bold format. |
| Q1 ⇒ Commercial available medium size
machines have a speed range of ____ 2000 to 2500 r.p.m. [other wrong options] [Discuss in forum] |
| Q2 ⇒ Hot rolled sheets have ____ value of
permeability low [other wrong options] [Discuss in forum] |
| Q3 ⇒ Hydrogen has a heat transfer co-efficient ____
times that of air 1.5 [other wrong options] [Discuss in forum] |
| Q4 ⇒ Direct water cooling of rotor winding
presents greater mechanical difficulties [other wrong options] [Discuss in forum] |
| Q5 ⇒ Tractive magnets are operated from either a.c or d.c. supply [other wrong options] [Discuss in forum] |
| Q6 ⇒ Dummy coil should not be used in large machines [other wrong options] [Discuss in forum] |
| Q7 ⇒ Disc windings are primarily used in high capacity transformers [other wrong options] [Discuss in forum] |
| Q8 ⇒ For large power transformers, self oil
cooled type or air blast type which of the
following values af current density may
be used ? 2.2 to 3.2 A/mm2 [other wrong options] [Discuss in forum] |
| Q9 ⇒ D.C. servomotors are used in purely D.C. control systems [other wrong options] [Discuss in forum] |
| Q10 ⇒ In a D.C. machine the number of brush
arms ____ is the number of poles. equal to [other wrong options] [Discuss in forum] |
| Q11 ⇒ The higher commutator peripheral
speeds generally lead to commutation difficulties [other wrong options] [Discuss in forum] |
| Q12 ⇒ The slip rings for wound rotor machines
are made of either brass or phosphor bronze [other wrong options] [Discuss in forum] |
| Q13 ⇒ A 3-phase winding carrying sinusoidal
currents produces harmonics of the
order (where N is an integer) n = 6 N ± 1 [other wrong options] [Discuss in forum] |
| Q14 ⇒ A large value of short-circuit current
indicates a good power factor [other wrong options] [Discuss in forum] |
| Q15 ⇒ Arc welding transformer is basically a step down transformer [other wrong options] [Discuss in forum] |
| Q16 ⇒ The shafts ofelectric motors is generally
supported in ball or roller bearings [other wrong options] [Discuss in forum] |
| Q17 ⇒ The efficiency of a machine should be
as as ____ possible to reduce the operating
cost. high [other wrong options] [Discuss in forum] |
| Q18 ⇒ The action of electromagnetic machines
can be related to which of the following
basic principles ? All of the above [other wrong options] [Discuss in forum] |
| Q19 ⇒ The heated parts of an electrical
machine dissipate heat into their surroundings
by which of the following
modes of heat dissipation ? All of the above [other wrong options] [Discuss in forum] |
| Q20 ⇒ The thermal conductivity of hydrogen
is ____ times that of air 7 [other wrong options] [Discuss in forum] |
| Or |