Questions -
Q1. What is the efficiency of a transformer that has an input of 600 VA and an output to a load of 580 VA?
A. 20 VA
B. 83.8%
C. 96.6%
D. 180 VA
Q2. If 120 VAC is applied to a transformer with a turns ratio of 6 : 1, what type of transformer is present and what is the output voltage of the secondary?
A. Step-down, 60 VAC
B. Step-up, 600 VAC
C. Step-down, 20 VAC
D. Step-up, 720 VAC
Q3. The primary current drawn by the transformer shown will be
A. 2 A.
B.10 A.
C. 5 A.
D. 50 A.
Q4. If the power in the primary circuit of a 4 : 1 transformer is 12 watts, what will be the power in the secondary of this transformer?
A. 12 watts
B. 3 watts
C. 4 watts
D. 48 watts
Q5. If the turns ratio of a transformer is 4 : 1 and the incoming voltage is 120 VAC. what Is the secondary voltage?
A. 240 VAC
B. 120 VAC
C. 480 VAC
D. 30 VAC
Q6. The secondary line-to-line voltage of a three-phase Y-Y-connected transformer bank is 115 VAC. What would be the secondary line to neutral voltage?
A. 199.2 V
B. 66.4 V
C. 50 V
D. 84.2 V
Q7. Three single-phase transformers, each having a secondary phase current of 10 A, are Delta-Delta-connected. The value of the secondary line current is
A. 57.8 A.
B. 1.73 A.
C. 17.3 A.
D. 578 A.