A transformer which can produce 8V from a 240v a.c. supply, has an efficiency of 80%. If the current in the secondary coil is 15A, calculate the current in ...
Question 1 Report
A transformer which can produce 8V from a 240v a.c. supply, has an efficiency of 80%. If the current in the secondary coil is 15A, calculate the current in the primary coil.
Answer Details
To solve this problem, we can use the formula for power:
Power (in watts) = Voltage x Current
Since the transformer has an efficiency of 80%, it means that 80% of the input power is transferred to the output. The remaining 20% is lost as heat. Therefore, we can say that:
Output Power = Input Power x Efficiency
We know the output voltage is 8V, and the output current is 15A. So, the output power can be calculated as:
Output Power = 8V x 15A = 120W
Substituting the values in the formula for efficiency, we get:
120W = Input Power x 0.80
Input Power = 120W/0.80 = 150W
Now, we can calculate the input current using the formula:
Input Power = Input Voltage x Input Current
Substituting the values, we get:
150W = 240V x Input Current
Input Current = 150W/240V = 0.625A
Therefore, the current in the primary coil is 0.625A.
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