GeneralG5C07

What transformer turns ratio matches an antenna’s 600-ohm feed point impedance to a 50-ohm coaxial cable?

A
Answer
Electrical principles
Type
A
3.5 to 1
B
12 to 1
C
24 to 1
D
144 to 1

Answer Notes

The relationship between a transformer's impedance ratio and its turns ratio is non-linear. Specifically, the impedance ratio is equal to the square of the turns ratio. First, calculate the required impedance ratio by dividing the two impedances: 600 ohms / 50 ohms = 12. Next, to find the turns ratio, you must take the square root of that impedance ratio. The square root of 12 is approximately 3.46, which rounds to 3.5. Therefore, the required turns ratio is 3.5 to 1. Distractors like 12 to 1 are incorrect because they skip the square root step entirely.
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What is the voltage output of a transformer with a 500-turn primary and a 1500-turn secondary when 120 VAC is applied to the primary?
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What is the equivalent capacitance of two 5.0-nanofarad capacitors and one 750-picofarad capacitor connected in parallel?