JEE Mains · Physics · STD 12 - Electromagnetic waves
- JEE Mains 2022
- Medium
- Numerical
A radar sends an electromagnetic signal of electric field \(\left( E _{0}\right)=2.25\,V / m\) and magnetic field \(\left( B _{0}\right)=1.5 \times 10^{-8}\,T\) which strikes a target on line of sight at a distance of \(3\,km\) in a medium After that, a pail of signal \((echo)\) reflects back towards the radar vitli same velocity and by same path. If the signal was transmitted at time \(t_{0}\) from radar. then after how much time (in \(\times 10^{-5}\,s\)) echo will reach to the radar?
Pick an option to check your answer.
Answer & Solution
Correct Answer
(B) \(4\)
Step-by-step Solution
Detailed explanation
\(C =\frac{ E _{0}}{ B _{0}}=\frac{2.25}{1.5 \times 10^{- s }}=1.5 \times 10^{8}\,ms ^{-1}\)
\(t =\frac{6 \times 10^{3}}{1.5 \times 10^{8}}=4 \times 10^{-5}\,s\)
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