Electrical and Electronics MCQS

Solve Circiut.

Please solve questions in sequence.

1. The degree of mechanical vibrations are produced by the laminations of a transformer depend on.............

A. Tightness of clamping
B. Guage of laminations
C. Size of laminations
D. All of the above

2. The No-load current drawn by transformer is usually what percent of the full load current?

A. 0.2% to 0.5%
B. 2% to 5%
C. 12% to 15%
D. 20% to 30%

3. The path of a magnetic flux in transformer should have.........

A. High resistance
B. High reluctance
C. Low resistance
D. Low reluctance

4. No-load on a transformer is carried out to determine?

A. Copper loss
B. Magnetising current
C. Magnetising current and loss
D. Efficiency of the transformer.

5. The dielectric strength of transformer oil is expected to be?

A. 1kv
B. 33kv
C. 100kv
D. 330kv

6. Sumpner's test is conducted in transformer to determine?

A. Temperature
B. Stray losses
C. All day efficiency
D. Non of above.

7. The transformer efficiency will be maximum when ?
A. Copper losses = hysteresis losses
B. Hysteresis losses = eddy current losses
C. Eddy current losses = copper losses
D. Copper losses = iron losses

8. The purpose of providing an iron core in transformer is to...?

A. Provide support to winding
B. Reduce hysteresis losses.
C. Decrease the reluctance of th magnetic path
D. Reduce the eddy current losses

9. Which of the following is not the part of transformer installation?

A. Conservator
B. Breather
C. Buchholz relay
D. Exciter

Please solve questions in sequence.

1.The efficiency of the transformer is mainly dependent on................losses.

A. Core
B. Copper
C. Stray
D. Dielectric

2. .........can be minimized by laminating the transformer core? And lamination of transformer is the made up of........

A. Hysteresis loss, cast Iron
B. Eddy current loss, silicon steel
C. Copper loss, wrought iron
D. Stray loss, cast steel

3.Oil is provided in an oiled-filled transformer for.......

A. Insulation
B. Lubrication
C. Cooling
D. A and C both

4. Air core transformer as compared to core transformer, has...

A. More copper loss
B. No copper loss
C. More core loss
D. No core loss

5 If a transformer is loaded, the secondary terminal voltage drops, it means power factor is

A. Zero
B. Leading
C. Unity
D. Lagging

6. Which of following is not a permanent magnetic material.

A. Chromium steel
B. Silicon steel
C. Cobalt steel
D. Alnico

Most common intereview question.
What is reason behind it?

The main mistry behind coulomb's formula😂😂😁

kVA rating is required for a transformer that must handle a maximum load current of 8 A with a secondary voltage of 2 kV?

A. 4 kVA
B. 0.25 kVA
C. 16 kVA
D. 8 kVA

Number of wires in three phase transformer are at distribution side from transformer to load?

A. Two
B. Three
C. Four
D. Five
E. None of above

Which parametes vary in transformer?
A. Frequenay, Power
B. Current, Voltage
C. All remains constant
D. All are variable