Equation of an EMW in a medium is given by $\mathrm { E } = 2 \sin \left( 2 \times 10 ^ { 15 } \mathrm { t } - 10 ^ { 7 } \mathrm { x } \right)$. Find refractive index of the medium. (A) $3 / 2$ (B) 2 (C) $5 / 3$ (D) $4 / 3$
Equation of an EMW in a medium is given by
$\mathrm { E } = 2 \sin \left( 2 \times 10 ^ { 15 } \mathrm { t } - 10 ^ { 7 } \mathrm { x } \right)$. Find refractive index of the medium.
(A) $3 / 2$
(B) 2
(C) $5 / 3$
(D) $4 / 3$