COMEDK · Physics · 23. Alternating Current
A transformer is used to light a \(100 \mathrm{~W}, 110 \mathrm{~V}\) lamp from a \(220 \mathrm{~V}\) supply. If the supply current is \(0.6 \mathrm{~A}\), then the efficiency of the transformer is
- A \(66 \%\)
- B \(76 \%\)
- C \(86 \%\)
- D \(96 \%\)
Answer & Solution
Correct Answer
(B) \(76 \%\)
Step-by-step Solution
Detailed explanation
For a transformer, Input voltage, \(V_{1}=220 \mathrm{~V}\) Input current, \({I}_{1}=0.6 \mathrm{~A}\) Output power, \(P_{2}=100 \mathrm{~W}\) From, input power, \(\quad P_{1}=V_{1} I_{1}\) \[ \begin{aligned} &=220 \times 0.6 \\ &=132 \mathrm{~W} \end{aligned} \] We know that,…
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