JEE Mains · Physics · STD 12 - 8. Electromagnetic waves
The electric field a plane electromagnetic wave is given by :
\(E _y=69 \sin \left[0.6 \times 10^3 x -1.8 \times 10^{11} t \right] V / m\).
The expression for magnetic field associated with this electromagnetic wave is _________ T.
- A \( B_{z} = 2.3 \times 10^{-7} \sin[0.6 \times 10^{3}x - 1.8 \times 10^{11}t] \)
- B \(B _z=2.3 \times 10^{-7} \sin \left[0.6 \times 10^3 x +1.8 \times 10^{11} t \right]\)
- C \(B_y=69 \sin \left[0.6 \times 10^3 x+1.8 \times 10^{11} t\right]\)
- D \(B_y=2.3 \times 10^{-7} \sin \left[0.6 \times 10^3 x-1.8 \times 10^{11} t\right]\)
Answer & Solution
Correct Answer
(A) \( B_{z} = 2.3 \times 10^{-7} \sin[0.6 \times 10^{3}x - 1.8 \times 10^{11}t] \)
Step-by-step Solution
Detailed explanation
\(\hat{ B }=\hat{ c } \times \hat{ E }\) \(\Rightarrow \quad \hat{ c }=\hat{ i }\) because phase of electric field is function of \(x\). \(\Rightarrow \quad \hat{ E }=\hat{ j }\) (given) \(\Rightarrow \quad \hat{ B }=\hat{ i } \times \hat{ j }=\hat{ k }\)…
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