NEET 2018 · PhysicsField directionsPrevious Year Question
An EM wave is propagating in a medium with velocity V = V î (along +x). The instantaneous oscillating electric field of this EM wave is along the +y axis. Then the direction of the oscillating magnetic field of the EM wave will be along
Answer: (B) +z direction. Answer: (B) +z direction.
- A.−y direction
- B.+z direction✓
- C.−z direction
- D.−x direction
Correct Answer
(B) +z direction
Solution & Explanation
Answer: (B) +z direction. For an EM wave the propagation direction is along E × B. With propagation along +x and E along +y, we need E × B ∝ +x. Since ĵ × k̂ = î, B must be along +z.
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