Electrical Machine - I (3140913) MCQs

MCQs of Transformers

Showing 1 to 10 out of 155 Questions
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1.
The core of the transformer must have
(a) Low reluctance
(b) High resistance
(c) High reluctance
(d) Low resistance
Answer:

Option (a)

2.
In a transformer, the magnetic coupling between the primary and secondary winding can be increased by
(a) increasing the number of turns
(b) using soft material for winding
(c) using the magnetic core of low reluctance
(d) using transformer oil of better quality
Answer:

Option (c)

3.
Air core transformer as compared to iron core transformer has
(a) more copper loss
(b) less magnetic core loss
(c) more magnetic core loss
(d) no magnetic core loss.
Answer:

Option (d)

4.
CRGO steel Laminations are used in the core of the transformer to reduce
(a) Eddy Current loss
(b) Hysteresis loss
(c) both Eddy current and Hysteresis losses
(d) Ohmic loss
Answer:

Option (c)

5.
What is the thickness of the laminated CRGO steel sheet used in the core of the transformer?
(a) Ranging from 0.018 mm to 0.035 mm.
(b) Ranging from 0.18 mm to 0.35 mm.
(c) Ranging from 1.8 mm to 3.5 mm.
(d) Ranging from 2.3 mm to 3.0 mm.
Answer:

Option (b)

6.
Insulated surface coating of a laminated sheet in the core of transformer helps to reduce
(a) Eddy current loss
(b) Hysteresis loss
(c) Both Eddy current and Hysteresis losses.
(d) none of the above.
Answer:

Option (a)

7.
In a transformer, the coils of primary and secondary are placed concentrically to achieve
(a) reduced leakage flux between the primary and secondary winding
(b) reduced copper losses in the windings
(c) reduced insulation cost of the windings
(d) reduced voltage per turn in the winding
Answer:

Option (a)

8.
The leakage flux is the flux inside the transformer which
(a) links either of the windings
(b) links both of the windings
(c) links the yoke of the core
(d) link windows of the core
Answer:

Option (a)

9.
In a core type transformer
(a) HV winding is placed nearer to the core limb.
(b) LV winding is placed nearer to the core limb.
(c) Any of the LV or HV can be placed nearer to the core limb.
(d) HV and LV windings are placed in different core limbs.
Answer:

Option (b)

10.
Why HV winding is always placed above the LV winding in a core type transformer?
(a) to reduce copper cost
(b) to reduce insulation cost
(c) to provide better cooling
(d) to provide more mechanical strength
Answer:

Option (b)

Showing 1 to 10 out of 155 Questions
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