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A plane electromagnetic wave propagates through vacuum in the x-direction. At one location, the electric field has a y-component of 9.3 V m⁻¹. The corresponding magnetic field component along the z-axis is:

1. 3.1 × 10⁻⁸ T
2. 3 × 10⁻⁵ T
3. 3 × 10⁻⁶ T
4. 9.3 × 10⁻⁶ T

Correct answer: 3.1 × 10⁻⁸ T

Solution

For an EM wave in vacuum, B = E/c = 9.3 / (3 x 10^8) = 3.1 x 10^-8 T.

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