Question is ⇒ ____ impose limitation on design., Options are ⇒ (A) Saturation, (B) Temperature rise, (C) Efficiency, (D) Power factor, (E) All above, Leave your comments or Download question paper.

Question is ⇒ ____ impose limitation on design., Options are ⇒ (A) Saturation, (B) Temperature rise, (C) Efficiency, (D) Power factor, (E) All above, Leave your comments or Download question paper. Previous question Next question


Q1.	____ impose limitation on design.
A.	Saturation [Wrong Answer]
B.	Temperature rise [Wrong Answer]
C.	Efficiency [Wrong Answer]
D.	Power factor [Wrong Answer]
E.	All above [Correct Answer]
View Answer 2 -1 Explanation:- Answer : E Discuss it below : !! OOPS Login [Click here] is required to post your answer/result Help other students, write article, leave your comments

Previous question Next question

Also Read Similar Questions Below :

⇒ ____ of lots are generally used in inductiion motors.
Closed type
Semi-closed type
Open type
Any of the above

⇒ Electrical machines having power outputs ranging from a few kW upto approxiuoriately 250 kW may be classified as ___
small size machines
medium size machines
large size machines
any of the above

⇒ Yokes with rectangular cross-section are used for
sraall capacity transformers
medium capacity transformers
large capacity transformers
any of the above

⇒ In D.C. machines, the ____ in field mmf results in increase in size and cost of machines.
increase
decrease
either of the above
none of the above

⇒ With direct water cooling it is possible to have ratings of about
200 MW
300 MW
400 MW
600 MW

⇒ Current density in the rotor bars of an induction motor may be taken between
1.5 to 2.5 A/mm²
3 to 4 A/mm²
4 to 7 A/mm²
8 to 10 A/mm²

⇒ In D.C. machines the usual limit of slot pitch is
between 5 to 10 mm
between 10 to 15 mm
between 15 to 20 mm
between 25 to 35 mm

⇒ Pitch of commutator segment should not be less than
1 mm
2 mm
3 mm
4 mm

⇒ The slot leakage can be calculated by making which of the following assumptions ?
The current in the slot conductors is uniformly distributed over their cross-section
The leakage path is straight across the slot and around the iron at the bottom
The permanence of air paths is only considered. The reluctance of iron paths is assumed as zero
All of the above

⇒ A current density of ____ is used for large power transformers with forced circulation of oil or with water cooling coils
1.5 to 2.5 A/mm²
3.5 to 4.5 A/mm²
4.0 to 5.0 A/mm²
5.4 to 6.2 A/mm²

⇒ The conductors for large sizes of D.C. machines are ____ in cross-section.
circular
triangular
rectangular
trapezoidal

⇒ Due to which of the following, harmonic fields are produced ?
Windings
Slotting
Saturation
Irregularities in the air gap

⇒ The area of each individual brush should be taken so that it does not carry
more than 20 A
more than 40 A
more than 50 A
mire than 70 A

⇒ Power transformers have rating
equal to 50 kVA
equal to 100 kVA
above 200 kVA
none of the above

⇒ The shafts ofelectric motors is generally supported in
cast-iron bearings
bush bearings
magnetic bearings
ball or roller bearings

⇒ In a D.C. machine the number of brush arms ____ is the number of poles.
less than
equal to
greater than
none of the above

⇒ ____ brushes are fragile and cause excessive wear of commutator.
Natural graphite
Hard carbon
Electro-graphitic
Metal graphite

⇒ It is a common practice to use deep bar rotors when ____ starting torque is required.
low
high
either (a) or (b)
none of the above

⇒ On which of the following variables heat convected depends ?
Power density
Temperature difference between heated surface and coolant
Thermal resistivity, density, specific heat
Gravitational constant

⇒ The surge phenomenon is particularly important in case of
low voltage transformers
medium voltage transformers
high voltage transformers
any of the above

⇒ By which of the following methods the temperature rise of windings and other parts may be determines ?
Thermonieter method
Resistance method
Embedded temperature detector method
Any of the above

⇒ D.C. servomotors are used in
purely D.C. control systems
purely A.C. control systems
both D.C. and A.C. control systems
none of the above

⇒ If the number of rotor slots is equal to the number of stator slots, the machine would refuse to start, this is known as
cogging
crawling
either of the above
none of the above

⇒ The cylindrical windings using circular conductors are used for current rating of
upto 20 A
upto 40 A
upto 60 A
upto 80 A

⇒ In a D.C. machine, the value of peripheral speed should not, normally, exceed
10 m/s
20 m/s
30 m/s
40 m/s

⇒ The higher commutator peripheral speeds
generally lead to commutation difficulties
always lead to commutation difficulties
never lead to commutation difficulties
any of the above

⇒ Which of the following methods is used for reduction/elimination of harmonic torques ?
Chording
Integral slot windings
Skewing
Increase in air gap length

⇒ Tap changing facility is generally provided on
current transformers
distribution transformers
high voltage transformers
none of the above

⇒ The change in flux linkages can be caused in which of the following ways ?
The flux is constant with respect to time and is stationary and the coil moves through it
The coil is stationary with respect to flux and the flux varies in magnitude with respect to time
Both the changes mentioned above occure together, i.e., the coil moves through a time varying field
All of the above

⇒ The distance between the starts of two consecutive coils measured in terms of coil sides is called
front pitch
winding pitch
commutator pitch
back pitch