A radar sends an electromagnetic signal of electric field ( E 0)=2.25 V / m and magnetic field (B0)=1.5 × 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 echo will reach to the radar?

Question

A radar sends an electromagnetic signal of electric field ( E 0)=2.25 V / m and magnetic field (B0)=1.5 × 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 echo will reach to the radar? (A) 2.0 × 10-5 s (B) 4.0 × 10-5 s (C) 1.0 × 10-5 s (D) 8.0 × 10-5 s

Tardigrade Admin · Accepted Answer

C =( E 0/ B 0)=(2.25/1.5 × 10-8)=1.5 × 108 ms -1 t =(6 × 103/1.5 × 108)=4 × 10-5 s

$2.0 \times 1 0^{- 5} s$

$4.0 \times 1 0^{- 5} s$

$1.0 \times 1 0^{- 5} s$

$8.0 \times 1 0^{- 5} s$

$C = \frac{E _{0}}{B _{0}} = \frac{2.25}{1.5 \times 1 0 ^{- 8}} = 1.5 \times 1 0^{8} m s^{- 1}$
$t = \frac{6 \times 1 0 ^{3}}{1.5 \times 1 0 ^{8}} = 4 \times 1 0^{- 5} s$

2.0×10−5s

4.0×10−5s

1.0×10−5s

8.0×10−5s

C=B0​E0​​=1.5×10−82.25​=1.5×108ms−1 t=1.5×1086×103​=4×10−5s

$2.0 \times 1 0^{- 5} s$

$4.0 \times 1 0^{- 5} s$

$1.0 \times 1 0^{- 5} s$

$8.0 \times 1 0^{- 5} s$

$C = \frac{E _{0}}{B _{0}} = \frac{2.25}{1.5 \times 1 0 ^{- 8}} = 1.5 \times 1 0^{8} m s^{- 1}$
$t = \frac{6 \times 1 0 ^{3}}{1.5 \times 1 0 ^{8}} = 4 \times 1 0^{- 5} s$