JEE Main20203 Sep 2020Morning ShiftPhysicsElectromagnetic WavesActual
The magnetic field of a plane electromagnetic wave is B → = 3 × 10 - 8 sin 200 π ( y + c t ) i ^ T . Where, c = 3 × 10 8 m s - 1 is the speed of light the corresponding electric filed is :
Options
- AE → = 9 sin [ 200 π ( y + ct ) k ^   V / m
- BE → = - 10 - 6 sin [ 200 π ( y + ct ) k ^   V / m
- CE → = 3 × 10 - 8 sin [ 200 π ( y + ct ) k ^   V / m
- DE → = - 9 sin [ 200 π ( y + ct ) k ^   V / m
Correct answer
A. E → = 9 sin [ 200 π ( y + ct ) k ^   V / m
Step-by-step solution
E 0 = c B 0 ∴ E → × B → ‖ C → ⇒ k ^ × i ^ = j ^ E → = 3 × 10 8 × 3 × 10 - 8 sin [ 200 π y + ct ( - k ^ )     = 9 sin [ 200 π y + ct ] ( - k ^ )