Practice Test: Question Set - 08
1. The degree of mechanical vibrations produced by the laminations of a transformer depends on
- (A) Tightness of clamping
- (B) Gauge of laminations
- (C) Size of laminations
- (D) All of the above
2. The primary winding of a power transformer should always be
- (A) Open
- (B) Shorted
- (C) Switched
- (D) Fused
3. Which of the following does not change in a transformer?
- (A) Current
- (B) Voltage
- (C) Frequency
- (D) All of the above
4. The purpose of providing an iron core in a transformer is to
- (A) Provide support to windings
- (B) Reduce hysteresis loss
- (C) Decrease the reluctance of the magnetic path
- (D) Reduce eddy current losses
5. A common method of cooling a power transformer is
- (A) Natural air cooling
- (B) Air blast cooling
- (C) Oil cooling
- (D) Any of the above
6. How many primary volts must be applied to a transformer with a turns ratio of 0.1 to obtain a secondary voltage of 9 V?
- (A) 9 V
- (B) 90 V
- (C) 900 V
- (D) 0.9 V
7. The power transformer is a constant
- (A) Voltage device
- (B) Current device
- (C) Power device
- (D) Main flux device
8. The transformer ratings are usually expressed in terms of
- (A) Volts
- (B) Amperes
- (C) kW
- (D) kVA
9. Which of the following property is not necessarily desirable in the material for transformer core?
- (A) Mechanical strength
- (B) Low hysteresis loss
- (C) High thermal conductivity
- (D) High permeability
10. The path of the magnetic flux in transformer should have
- (A) High reluctance
- (B) Low reactance
- (C) High resistance
- (D) Low resistance
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