JEE Main2017PhysicsElectromagnetic WavesActual
The electric field component of a monochromatic radiation is given by E → = 2 E 0 cos k z cos ω t i ^ , Its magnetic field B → is then given by:
Options
- A2 E 0 c sin k z sin ω t   j ^
- B2 E 0 c cos k z cos ω t   j ^
- C2 E 0 c sin k z cos ω t   j ^
- D-2 E 0 c sin k z sin ω t   j ^
Correct answer
A. 2 E 0 c sin k z sin ω t   j ^
Step-by-step solution
d E d z = - d B d t d E d z = - 2 E 0 K sin ⁡ k z cos ⁡ ω t = - d B d t d B = + 2 E 0 K sin ⁡ k z cos ⁡ ω t   d t B =   + 2 E 0 K sin ⁡ k z ∫ cos ⁡ ω t   d t = + 2 E 0 k ω sin ⁡ k z sin ⁡ ω t E 0 B 0 = ω k = C B = 2 E 0 C sin ⁡ k z sin ⁡ ω t Propagation of EM radiation, Electric field oscillation and Magnetic field oscillation are perpendicular to each other. Since propagation of EM radiation is x - a