Practice Test: Question Set - 02
1. Which of the following properties is not necessarily desirable for the material for transformer core?
- (A) Low hysteresis loss
- (B) High permeability
- (C) High thermal conductivity
- (D) Adequate mechanical strength
2. Gas is usually not liberated due to dissociation of transformer oil unless the oil temperature exceeds
- (A) 50°C
- (B) 80°C
- (C) 100°C
- (D) 150°C
3. Material used for construction of transformer core is usually
- (A) Wood
- (B) Copper
- (C) Aluminium
- (D) Silicon steel
4. A transformer
- (A) Changes ac
to dc
- (B) Changes dc
to ac
- (C) Steps up or
down dc voltages
- (D) Steps up or
down ac voltages
5. The mutual inductance when k = 0.65, L1 = 2 μH, and L2 = 5 μH is
- (A) 2 mH
- (B) 2 μH
- (C) 4 μH
- (D) 8 μH
6. What 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
7. If the percentage impedances of the two transformers working in parallel are different, then
- (A) Transformers will be overheated
- (B) Power factors of both the transformers will be same
- (C) Parallel operation will be not possible
- (D) Parallel operation will still be possible, but the
power factors at which the two transformers operate will be different from the
power factor of the common load
8. A transformer consists of two or more cores that are electrically coupled on a common core.
- (A) True
- (B) False
9. If the voltage is stepped up, the current is stepped down, and vice versa.
- (A) True
- (B) False
10. A transformer oil must be free from
- (A) Sludge
- (B) Odour
- (C) Gases
- (D) Moisture
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