Question 159Electricity/Electronics - 1st Asst/Chief70% to pass
What is the maximum current allowed to be drawn from the secondary of a 2 kVA step-down transformer with a turn’s ratio of four to one if connected across a 440 volt line?
AI Explanation
The correct answer is C) 18.1 amps.
To calculate the maximum current that can be drawn from the secondary of the 2 kVA step-down transformer, we need to use the formula for power in a transformer:
Power (P) = Voltage (V) x Current (I)
Given:
- Transformer rating: 2 kVA (2000 VA)
- Turn's ratio: 4:1 (primary to secondary)
- Primary voltage: 440 V
To find the secondary voltage, we divide the primary voltage by the turn's ratio:
Secondary voltage = 440 V / 4 = 110 V
Now, we can use the power formula to calculate the maximum current that can be drawn from the secondary:
Power (P) = 2000 VA
Voltage (V) = 110 V
Current (I) = P / V
Current (I) = 2000 VA / 110 V = 18.1 amps
Therefore, the maximum current allowed to be drawn from the secondary of the 2 kVA step-down transformer with a turn's ratio of four to one, if connected across a 440-volt line, is 18.1 amps.
The other options are incorrect because:
A) 1.1 amps is too low for a 2 kVA transformer.
B) 4.5 amps is too low for a 2 kVA transformer.
D) 22.7 amps is too high for a 2 kVA transformer.
Related Questions
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