DC GENERATOR ONLINE TEST 1
DC GENERATOR ONLINE TEST 1
ITI ELECTRICIAN TRADE DC GENERATORS TEST NO - 1
ITI ELECTRICIAN TRADE DC GENERATORS TEST NO - 1
Quiz
- How to create online multiple choice quiz In Blog
Laminations of core are generally made of- case iron
- carbon
- silicon steel
- stainless steel
- Which of the following could be lamina-proximately the thickness of laminations of a D.C. machine ?
- 0.005 mm
- 0.05 mm
- 0.5 m
- 5 m
- The armature of D.C. generator is laminated to
- reduce the bulk
- provide the bulk
- insulate the core
- reduce eddy current loss
- The resistance of armature winding depends on
- length of conductor
- cross-sectional area of the conductor
- number of conductors
- all of the above
- The field coils of D.C. generator are usually made of
- mica
- copper
- cast iron
- carbon
- The commutator segments are connected to the armature conductors by means of
- copper lugs
- resistance wires
- insulation pads
- brazing
- In a commutator
- copper is harder than mica
- mica and copper are equally hard
- mica is harder than copper
- none of the above
- In D.C. generators the pole shoes are fastened to the pole core by
- rivets
- counter sunk screws
- brazing
- welding
- According to Fleming's right-hand rule for finding the direction of induced e.m.f., when middle finger points in the direction of induced e.m.f., forefinger will point in the direction of
- motion of conductor
- lines of force
- either of the above
- none of the above
- Fleming's right-hand rule regarding direction of induced e.m.f., correlates
- magnetic flux, direction of current flow and resultant force
- magnetic flux, direction of motion and the direction of e.m.f. induced
- magnetic field strength, induced voltage and current
- magnetic flux, direction of force and direction of motion of conductor
- While applying Fleming's right-hand rule to And the direction of induced e.m.f., the thumb points towards
- direction of induced e.m.f.
- direction of flux
- direction of motion of the conductor if forefinger points in the direction of generated e.m.f.
- direction of motion of conductor, if forefinger points along the lines of flux
- The bearings used to support the rotor shafts are generally
- ball bearings
- bush bearings
- magnetic bearmgs
- needle bearings
- In D.C. generators, the cause of rapid brush wear may be
- severe sparking
- rough commutator surface
- imperfect contact
- any of the above
- In lap winding, the number of brushes is always
- double the number of poles
- same as the number of poles
- half the number of poles
- two
- For a D.C. generator when the number of poles and the number of armature conductors is fixed, then which winding will give the higher e.m.f. ?
- Lap winding
- Wave winding
- Either of (a) and (b) above
- Depends on other features of design
- In a four-pole D.C. machine
- all the four poles are north poles
- alternate poles are north and south
- all the four poles are south poles
- two north poles follow two south poles
- Copper brushes in D.C. machine are used
- where low voltage and high currents are involved
- where high voltage and small cur-rents are involved
- in both of the above cases
- in none of the above cases
- A separately excited generator as compared to a self-excited generator
- is amenable to better voltage con-trol
- is more stable
- has exciting current independent of load current
- has all above features
- In case of D.C. machines, mechanical losses are primary function of
- current
- voltage
- speed
- none of above
- Iron losses in a D.C. machine are independent of variations in
- speed
- load
- voltage
- speed and voltage
DC GENERATOR ONLINE TEST 1
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on
March 31, 2020
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