GATE 2017 EC (EC2) – Question 35
A two-wire transmission line terminates in a television set. The VSWR measured on the line is 5.8. The percentage of power reflected from the television set is ________.
Practise this question in The GATE Grind →
Show answer and explanation
Correct answer: 48.0 to 51.0
Explanation
VSWR S and voltage-reflection magnitude are related by $|\Gamma|=(S-1)/(S+1)$. Thus $|\Gamma|=4.8/6.8=12/17$.
Reflected power fraction is the square of this voltage ratio, not the ratio itself. Hence the percentage is $100(12/17)^2=49.827\ldots\%$.
The required answer is **49.83%**, within the official 48–51% interval.