AP EAMCET201824 Apr 2018Morning ShiftPhysicsElectromagnetic WavesActual
An electromagnetic wave of frequency 45 MHz travels in free space along X -axis. At some point and at some instant, the electric field has a maximum value of 750 NC ⁻¹ along Y -axis. The magnetic field at this position and time is
Options
- A2.5 10⁻⁶ j
- B5 10⁻⁶ k T
- C2.5 10⁻⁶ k T
- D2.5 10⁻⁶ i T
Correct answer
C. 2.5 10⁻⁶ k T
Step-by-step solution
Relation between electric and magnetic field in electromagnetic wave aligned & B= E c & E=750 ~N / C aligned Speed of light, aligned c & =3 10^8 ~m / s B & = 750 3 10^8 B & =2.5 10⁻⁶ ~T aligned As, B must be perpendicular to both c and E , i.e.it is along Z -axis. B=2.5 10⁻⁶ k T