Electro Magnetic Induction And Alternating Currents Question 222
Question: A 220 volts input is supplied to a transformer. The output circuit draws a current of 2.0 ampere at 440 volts. If the efficiency of the transformer is 80%, the current drawn by the primary windings of the transformer is
Options:
A) 3.6 ampere
B) 2.8 ampere
C) 2.5 ampere
D) 5.0 ampere
Show Answer
Answer:
Correct Answer: D
Solution:
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$ \frac{V_{2}}{V_{1}}=0.8\frac{I_{1}}{I_{2}}\Rightarrow \frac{V_{2}I_{2}}{V_{1}I_{1}}=0.8 $
$ V_{1}=220V,I_{2}=2.0A,V_{2}=440V $
$ I_{1}=\frac{V_{2}I_{2}}{V_{1}}\times \frac{10}{8}=\frac{440\times 2\times 10}{220\times 8}=5A $
