In a transformer maximum efficiency occurs at 80% of a full load then ...
At maximum efficiency
Pc = Pi
Copper loss at 70% of full load = (0.8)2 Pc
Iron loss at rated voltage = Pi
25 P
i = 16 P
c
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In a transformer maximum efficiency occurs at 80% of a full load then ...
Relation between iron loss at rated voltage (Pi) and copper loss at full load:
To understand the relation between iron loss (Pi) and copper loss (Pc) in a transformer, let's first define these terms.
- Iron loss (Pi): Iron loss refers to the power loss that occurs in the core of the transformer due to hysteresis and eddy current losses. It is also known as core loss or no-load loss. Iron loss is constant and independent of the load current.
- Copper loss (Pc): Copper loss refers to the power loss that occurs in the windings of the transformer due to the resistance of the copper conductors. Copper loss increases with the square of the load current.
Relation at maximum efficiency:
The maximum efficiency of a transformer occurs when the copper loss is equal to the iron loss. At this point, the transformer operates most efficiently.
Given that the maximum efficiency occurs at 80% of full load, we can express the copper loss at full load as 100% and the copper loss at maximum efficiency as 80%.
Let's assume the iron loss at rated voltage (Pi) is 'x'.
- Iron loss at rated voltage (Pi) = x
- Copper loss at full load = 100%
- Copper loss at maximum efficiency = 80%
To find the relation between Pi and Pc, we can set up a proportion:
Pi / Pc = (Iron loss at rated voltage) / (Copper loss at full load)
Substituting the given values:
x / Pc = x / 100
Cross-multiplying:
100 * x = x * Pc
Simplifying:
100 = Pc
Therefore, the relation between iron loss at rated voltage (Pi) and copper loss at full load is:
100 * Pi = Pc
Correct option:
The correct answer is option A: 25Pi = 16Pc.