NEET2020PhysicsElectromagnetic WavesActual
The magnetic field in a plane electromagnetic wave is given by: B y = 2 × 10 - 7 sin π × 10 3 x + 3 π × 10 11 t   T . Calculate the wavelength.
Options
- Aπ × 10 3   m
- B2 × 10 - 3   m
- C2 × 10 3   m
- Dπ × 10 - 3   m
Correct answer
B. 2 × 10 - 3   m
Step-by-step solution
Recall the standard form of the equation of electromagnetic wave in terms of the magnetic field, B y = B 0 sin k x + ω t   T , here B 0 is the magnitude of magnetic field, k = 2 π λ   &   ω = 2 π f . The equation is given in the question, B y = 2 × 10 - 7 sin π × 10 3 x + 3 π × 10 11 t   T ⇒ λ = 2 π k = 2 π π × 10 3 ⇒ λ = 2 × 10 - 3   m .