Question

The oscillating magnetic field in a plane dectromagnetic wave is given by \( B_{y}=5 \times 10^{-6} \) \( \sin 1000 \pi\left(5 x-4 \times 10^{8} t\right) T \). The amplitude of electric field will be 

(a) \( 15 \times 10^{2} V m ^{-1} \) 

(b) \( 5 \times 10^{-6} V m ^{-1} \) 

(c) \( 16 \times 10^{12} V m ^{-1} \) 

(d) \( 4 \times 10^{2} V m ^{-1} \)

Answer 1

v=w(omega)/k
v=Eo/Bo
w/k=Eo/Bo
4 × 10^8/5=Eo/ 5 × 10^-6

after solving answer is d=4x10^2

Answer 2

Correct option is (d) 4 x 10² Vm^-1

Given,

\(B_y = 5 \times 10^{-6} \sin(5000\pi x - 4000\pi \times 10 ^8t).T\)

\(B_0 = 5 \times 10^{-6}\)

\(V = \frac wk\)

\(V = \frac{4 \times 10^8}5\)

\(V= 8\times 10^7\)

\(E_0 = VB_0\)

\(E_0 = 8\times 10^7\times5 \times 10^{-6}\)

\(E_0 = 4 \times 10^2 \,v/m\)