Question

A sinusoidal wave is reflected at the surface of a medium whose properties are such that half the incident energy is absorbed. Consider the field that results from the superposition of the incident and the reflected wave. An observer stationed somewhere in this field finds the local electric field oscillating with a certain amplitude E. What is the ratio of the largest such amplitude noted by an observer to the smallest amplitude noted by any observer

Answer 1

Answer:

$\frac{Ei + Er}{Ei-Er}$

Explanation:

Ratio of the largest amplitude to the smallest amplitude is called voltage standing wave ratio ( along a transmission line )

Determine the ratio of the largest such amplitude noted by an observer tot the smallest amplitude

Expression for VSWR

VSWR =  $\frac{1 + \sqrt{\frac{Pr}{Pi} } }{1 - \sqrt{\frac{Pr}{Pi} } }$    where ; Pr = reflected power , Pi = Incident power

hence the ratio of the largest amplitude to the smallest amplitude

= $\frac{Emax}{Emin}$ = $\frac{Ei + Er}{Ei-Er}$  where ; Ei = amplitude of incident wave, Er = amplitude of reflected wave