An audio transformer has a turn ratio of 9, What is its impedance ratio? A. 81 B. 85 C. 6 D. 9 E. None of the above

The correct answer is $\boxed{\text{A}}$.

The impedance ratio of a transformer is the square of the turn ratio. In this case, the turn ratio is

24.8 41.5 48.3 47.8C117.2 448 288 448 288 448s170.8 0 213.4-11.5c23.5-6.3 42-24.2 48.3-47.8 11.4-42.9 11.4-132.3 11.4-132.3s0-89.4-11.4-132.3zm-317.5 213.5V175.2l142.7 81.2-142.7 81.2z"/> Subscribe on YouTube