GATE EC 2002 Electromagnetics Solution 8

GATE EC 2002 Electromagnetics Solution Q 8

A person with a receiver is 5 km away from the transmitter. What is the distance that this person must move further to detect a 3-dB decrease in signal strength ?

(a) 942 m

(b) 2070 m

(c) 4978 m

(d) 5320 m

Ans :- (b)

Explanation

Signal strength = \frac P{4\pi R^2}

P_1=\frac P{4\pi\left(5000\right)^2} P_2=\frac P{4\pi\left(x\right)^2}

As in the question, given as 3db decrease, we have

\frac{P_2}{P_1}=\frac12 \left(\frac{5000}x\right)^2=\frac12 x=5000\sqrt2 \therefore Ans=5000\sqrt2-5000=2071\;m

Become PRO At Electromagnetics Basics With Our 4 Ultimate Visual FREE E-Books On Coordinate Systems & Transformations

GET THEM NOW!

MORE QUESTIONS

Sign up for our Newsletter

Scroll to Top

NAGPUR UNIVERSITY

PUNE UNIVERSITY

MUMBAI UNIVERSITY