A) \[30%\]
B) \[50%\]
C) \[90%\]
D) \[10%\]
Correct Answer: C
Solution :
The efficiency of transformer \[\text{=}\frac{\text{Energy}\,\,\text{obtained}\,\,\text{from}\,\,\text{the}\,\,\text{secondary}\,\,\text{coil}}{\text{Energy}\,\,\text{given}\,\,\text{to}\,\,\text{the}\,\,\text{primary}\,\,\text{coil}}\] or \[\eta =\frac{\text{Output}\,\,\text{power}}{\text{Input}\,\,\text{power}}\] or \[\eta =\frac{{{V}_{s}}{{I}_{s}}}{{{V}_{p}}{{I}_{p}}}\] Given, \[{{V}_{s}}{{I}_{s}}=100W,\,\,{{V}_{p}}=220\,\,V,\,\,{{I}_{p}}=0.5\,\,A\] Hence, \[\eta =\frac{100}{225\times 0.5}=0.90=90%\] Note The efficiency of an ideal transformer is \[1\] (or\[100%)\]. But in practice due to loss in energy, the efficiency of transformer is always less than \[1\] (or less than\[100%)\].You need to login to perform this action.
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