Alternating Current

JEE Main level, numerical answer, medium

172 of 190

Question 172 of 190

A power transmission line feeds input power at 2.3kV2.3kV to a step down transformer with its primary winding having 3000turns3000\text{turns}. The output power is delivered at 230V230V by the transformer. The current in the primary of the transformer is 5A5A and its efficiency is 9090%. The winding of transformer is made of copper. The output current of transformer is ____AA.

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Answer: 45

Given:
Input power, Pi=2300×5watt{P}_{i}=2300\times 5\text{watt}
Output power, P0=2300×5×0.9{P}_{0}=2300\times 5\times 0.9
Now, we can write η=PoutPin=VSISVPIP\eta =\dfrac{{P}_{out}}{{P}_{in}}=\dfrac{{V}_{S}{I}_{S}}{{V}_{P}{I}_{P}}
⇒0.9=230IS2300×5⇒IS=45A.\Rightarrow 0.9=\dfrac{230{I}_{S}}{2300\times 5} \Rightarrow {I}_{S}=45A.

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