Q21 / 117 · NTA Abhyas (NEET) 2020 · Physics · Alternating Current

For an ideal step-down transformer, the quantity which is constant for both the coils is

A
Current in the coils
B
Voltage across the coils
C
Resistance of coils
Correct answer
D
Power in the coils

Solution

For an ideal step-down transformer power is constant for both the coils.

i.e., Input power = Output power

∴ V_{p} I_{p} = V_{s} I_{s}

or

\frac{V_{p}}{V_{s}} = \frac{I_{s}}{I_{p}}

Hence, the correct answer is option: 'D'.

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