Electrical Machine Design MCQ

Test your knowledge with important Electrical Machine Design MCQ and their applications. These MCQs are beneficial for competitive exams too. Explore 30 + more Electrical Machine Design MCQs at Bissoy

• The power of a n-phase circuit can be measured by using a minimum of
  ক

  (n – 1) wattmeter elements

  খ

  n wattmeter elements

  গ

  (n + 1) wattmeter elements

  ঘ

  2n wattmeter elements
• In self cooled motors the cooling time constant is about ______ than the heating time constant because cooling conditions are worse at standstill.
  ক

  2 to 3 times greater

  খ

  3 to 4 times greater

  গ

  4 to 5 times greater

  ঘ

  none of the above
• In a single phase power factor meter the phase difference between the currents in the two pressure coils is
  ক

  exactly 0°

  খ

  approximately 0°

  গ

  exactly 90°

  ঘ

  approximately 90°
• Transformers with a capacity of up to _____ have a cooling radiator system with natural cooling
  ক

  2 MVA

  খ

  5 MVA

  গ

  7.5 MVA

  ঘ

  10 MVA
• Helical windings are used in
  ক

  distribution transformers

  খ

  power transformers

  গ

  shell type transformers

  ঘ

  none of the above
• A power factor meter has
  ক

  one current circuit and two pressure circuits

  খ

  one current circuit and one pressure circuit

  গ

  two current circuits and one pres¬sure circuit

  ঘ

  none of the above
• D.C. servomotors are used in
  ক

  Purely D.C. control systems

  খ

  Purely AC. control systems

  গ

  Both D.and Acontrol systems

  ঘ

  None of the above
• For measurement of inductance having high value, we should use
  ক

  Maxwell’s bridge

  খ

  Maxwell Wein bridge

  গ

  Hay’s bridge

  ঘ

  Any of the above
• The laminations of the armature of a D.C. machine are usually _____ thick.
  ক

  0.1 to 0.2 mm

  খ

  0.2 to 0.3 mm

  গ

  0.3 to 0.4 mm

  ঘ

  0.4 to 0.5 mm
• Murray loop test can be used for location of
  ক

  ground fault on a cable

  খ

  short circuit fault on a cable

  গ

  both the ground fault and the short-circuit fault

  ঘ

  none of the above
• The power factor of a single phase load can be calculated if the instruments available are
  ক

  one voltmeter and one ammeter

  খ

  one voltmeter, one ammeter and one wattmeter

  গ

  one voltmeter, one ammeter and one energy meter

  ঘ

  any of the above
• In a D.C. machine the current per brush arm should not be more than
  ক

  100 A

  খ

  200 A

  গ

  300 A

  ঘ

  400 A
• The resistivity of water should not be less than
  ক

  10 Q m

  খ

  100 Q m

  গ

  1000 Q m

  ঘ

  2000 Q m
• If an instrument has cramped scale for larger values, then it follows
  ক

  square law

  খ

  logarithmic law

  গ

  uniform law

  ঘ

  none of the above
• Tractive magnets are operated from
  ক

  a.c. supply

  খ

  d.c. supply

  গ

  either a.c. or d.c. supply

  ঘ

  none of the above
• According to application, instruments are classified as
  ক

  switch board

  খ

  portable

  গ

  both (A) and (B)

  ঘ

  moving coil

  ঙ

  moving iron
• Direct water cooling of rotor winding presents
  ক

  No mechanical difficulties

  খ

  Lesser mechanical difficulties

  গ

  Greater mechanical difficulties

  ঘ

  None of the above
• Most sensitive galvanometer is
  ক

  elastic galvanometer

  খ

  vibration galvanometer

  গ

  Duddlb galvanometer

  ঘ

  spot ballistic galvanometer
• Which of the following in an application of D.C. motors?
  ক

  Traction

  খ

  Drives for process industry

  গ

  Battery driven vehicles

  ঘ

  Automatic control

  ঙ

  All of the above
• The scale of a rectifier instrument is
  ক

  linear

  খ

  non-linear

  গ

  either (A) or (B)

  ঘ

  neither (A) nor (B)
• The operation of a D.C. machine with large air gap lengths is comparatively
  ক

  quiet

  খ

  noisy

  গ

  either of the above

  ঘ

  none of the above
• In a D.C. machine the number of brush arms is _____ the number of poles.
  ক

  less than

  খ

  equal to

  গ

  greater than

  ঘ

  none of the above
• The change in flux linkages can be caused in which of the following ways ?
  ক

  The flux is constant with respect to time and is stationary and the coil moves through it

  খ

  The coil is stationary with respect to flux and the flux varies in magnitude with respect to time

  গ

  Both the changes mentioned above occur together, i.e., the coil moves through a time vary-ing field

  ঘ

  All of the above
• The high voltage winding is usually which of the following type ?
  ক

  Cylindrical winding with circular conductors

  খ

  Cross-over winding with either circular or small rectangular conductors

  গ

  Continuous disc type winding with rectangular conductors

  ঘ

  All of the above types
• Damping of the Ballistic galvanometer is made small to
  ক

  get first deflection large

  খ

  make the system oscillatory

  গ

  make the system critically damped

  ঘ

  get minimum overshoot
• Commonly used standard capacitor is
  ক

  spherical type

  খ

  concentric cylindrical type

  গ

  electrostatic type

  ঘ

  multilayer parallel plate type
• Aluminium when adopted as a conductor material in ______ transformers, decreases the overall cost of the transformer
  ক

  small size

  খ

  medium size

  গ

  large size

  ঘ

  any of the above size
• Which of the following is an essential part of a motor meter ?
  ক

  An operating torque system

  খ

  A braking device

  গ

  Revolution registering device

  ঘ

  All of the above
• The gravity controlled instrument has crowded scale because current is proportional to
  ক

  balancing weight

  খ

  deflection angle

  গ

  sine of deflection angle

  ঘ

  All of the above
• A direct current can be measured by
  ক

  a D.C. potentiometer directly

  খ

  a D.C. potentiometer in conjunction with a standard resistance

  গ

  a D.potentiometer in conjunction with a volt ratio box

  ঘ

  none of the above