Electrical Transformers MCQ - Set 05 - ObjectiveBooks

Electrical Transformers MCQ - Set 05

Practice Test: Question Set - 05

1. In a transformer routine efficiency depends upon
    (A) Supply frequency
    (B) Load current
    (C) Power factor of load
    (D) Both (B) and (C)

2. When a 6 V battery is connected across the primary of a transformer with a turns ratio of 8, the secondary voltage is
    (A) 0 V
    (B) 6 V
    (C) 48 V
    (D) 0.75 V

3. Greater the secondary leakage flux
    (A) Less will be the secondary induced e.m.f.
    (B) Less will be the primary induced e.m.f.
    (C) Less will be the primary terminal voltage
    (D) None of the above

4. The chemical used in breather is
    (A) Asbestos fiber
    (B) Silica sand
    (C) Sodium chloride
    (D) Silica gel

5. A reflective load is a load as it appears to the source in the primary of a transformer.
    (A) True
    (B) False

6. The main reason for generation of harmonics in a transformer could be
    (A) Fluctuating load
    (B) Poor insulation
    (C) Mechanical vibrations
    (D) Saturation of core

7. A transformer can have zero voltage regulation at
    (A) Leading power factor
    (B) Lagging power factor
    (C) Unity power factor
    (D) Zero power factor

8. When the turns ratio of a transformer is 20 and the primary ac voltage is 12 V, the secondary voltage is
    (A) 12 V
    (B) 120 V
    (C) 240 V
    (D) 2,400 V

9. During short circuit test iron losses are negligible because
    (A) The current on secondary side is negligible
    (B) The voltage on secondary side does not vary
    (C) The voltage applied on primary side is low
    (D) Full-load current is not supplied to the transformer

10. Iron loss of a transformer can be measured by
    (A) Low power factor wattmeter
    (B) Unity power factor wattmeter
    (C) Frequency meter
    (D) Any type of wattmeter

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