Consider an electromagnetic wave propagating in vacuum. Choose the correct statement: (a) For an electromagnetic wave propagating in +x direction the electric field is E = 1/√(2)Eyz(x,t)(y - z) and the magnetic field is B = 1/√(2)Byz(x,t)(y + z) (b) For an electromagnetic wave propagating in +x direction the electric field is E = 1/√(2)Eyz(y,z,t)(y + z) and the magnetic field is B = 1/√(2)Byz(y,z,t)(y + z) (c) For an electromagnetic wave propagating in + y direction the electric field is E = 1/√(2)Eyz(x,t)y and the magnetic field is B = 1/√(2)Byz(x,t)z (d) For an electromagnetic wave propagating in + y direction the electric field is E = 1/√(2)Eyz(x,t)z and the magnetic field is B = 1/√(2)Bz(x,t)y

Answer: (a). For travel along +x the fields depend on (x,t) and must satisfy E⊥ B with E× B along + x. (a): ( y- z)·( y+ z) = 0 and ( y- z)×( y+ z) = 2 x. Correct. (b): E∥ B and depends on (y,z); (c), (d): fields depend on x but wave said to go along y, and one field lies along y. Wrong. So the answer is (a).

Consider an electromagnetic wave propagating in vacuum. Choose the… | JEE Main 2016 (10 Apr, Shift 1)

Q77JEE Main 2016 · 10 APR · SHIFT 1Medium

Nature of EM Waves & Wave Equation

Consider an electromagnetic wave propagating in vacuum. Choose the correct statement:

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Answer: (a)

For travel along $+x$ the fields depend on $(x,t)$ and must satisfy $\vec E\perp\vec B$ with $\vec E\times\vec B$ along $+\hat x$ .
(a): $(\hat y-\hat z)\cdot(\hat y+\hat z) = 0$ and $(\hat y-\hat z)\times(\hat y+\hat z) = 2\hat x$ . Correct.
(b): $\vec E\parallel\vec B$ and depends on $(y,z)$ ; (c), (d): fields depend on $x$ but wave said to go along $y$ , and one field lies along $y$ . Wrong.
So the answer is (a).

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