Verified Solution • 2025–26 Session moderate

QJEEM22Phc3f1: JEE Main 2022 Physics - Class 12 JEEM22Phc3f1 Solution: A radar sends an electromagnetic signal of electric field (E 0…

A radar sends an electromagnetic signal of electric field (E0) = 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 part of signal (echo) reflects back towards the radar with 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?

Multiple Choice Options

  • A 2.0 × 10−5 s
  • B 4.0 × 10−5 s
  • C 1.0 × 10−5 s
  • D 8.0 × 10−5 s

Step-by-Step Verified Solution

E0 = 2.25 V/m

B0 = 1.5 × 10−8 T

⇒E0B0=1.5×108 m/s

⇒ Refractive index = 2

Distance to be travelled = 6 km

Time taken =6×1031.5×108=4×10−5 s

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