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A electromagnetic wave going through a medium is given by `E = E_(0)sin (kx – omegat) and B = B_(0) sin (kx – omegat)` then

A

`E_(0)k=B_(0)omega`

B

If Electric is in Z direction them magnetic field should be in -y direction.

C

Both ‘A’ and ‘B’ are correct

D

Only A is correct

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem regarding the electromagnetic wave represented by the equations \( E = E_0 \sin(kx - \omega t) \) and \( B = B_0 \sin(kx - \omega t) \), we will analyze the relationships between the electric field \( E \), magnetic field \( B \), and their respective directions. ### Step 1: Understanding the Wave Equations The given equations represent a plane electromagnetic wave traveling through a medium. The electric field \( E \) and magnetic field \( B \) are both sinusoidal functions of space and time. ### Step 2: Direction of Propagation For electromagnetic waves, the direction of propagation is given by the cross product of the electric field \( E \) and the magnetic field \( B \). The relationship can be expressed as: \[ \mathbf{k} = \mathbf{E} \times \mathbf{B} \] where \( \mathbf{k} \) is the direction of wave propagation. ### Step 3: Identifying Directions Assuming the electric field \( E \) is in the z-direction, we can write: \[ \mathbf{E} = E_0 \hat{z} \] If the magnetic field \( B \) is in the y-direction, we can write: \[ \mathbf{B} = B_0 \hat{y} \] ### Step 4: Applying the Right-Hand Rule Using the right-hand rule: - Point your fingers in the direction of \( \mathbf{E} \) (z-direction). - Curl your fingers towards \( \mathbf{B} \) (y-direction). - Your thumb will point in the direction of wave propagation (x-direction). ### Step 5: Establishing the Relationship Between E and B In electromagnetic waves, the magnitudes of the electric and magnetic fields are related by the equation: \[ \frac{E_0}{B_0} = c \] where \( c \) is the speed of light in the medium. ### Step 6: Relating k and ω The wave vector \( k \) and angular frequency \( \omega \) are related to the speed of light \( c \) as follows: \[ c = \frac{\omega}{k} \] From the above, we can express the relationship between the electric field and magnetic field magnitudes: \[ E_0 = c B_0 \implies E_0 k = B_0 \omega \] ### Conclusion Based on the analysis, we find that: 1. The relationship \( E_0 k = B_0 \omega \) holds true. 2. The directions of \( E \) and \( B \) are perpendicular to each other and to the direction of wave propagation. Thus, both statements regarding the relationships and directions are correct. ### Final Answer Both statements are correct: \( E_0 k = B_0 \omega \) and the directions of \( E \) and \( B \) are perpendicular to each other. ---
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Knowledge Check

  • If an electromagnetic wave propagation through vaccum is described by E_(y)=E_(0)sin (kx-omegat), B _(2)sin (kx-omegat) , then

    A
    `E_(o)k=B_(0)omega`
    B
    `E_(0)B_(0)=omegak`
    C
    `E_(0)omega=B_(0)k`
    D
    `E_(0)B_(0)=(omega)/(k)`
  • An electromagnetic wave going through vacuum is described by E= E_0 sin(kx- omega t), B=B_0sin(kx-omega t) . Then

    A
    `(E_0)k =(B_0)omega`
    B
    `(E_0) (B_0)=omega k`
    C
    `(E_0)omega = B_0 k `
    D
    none of these .
  • An electromagnetic wave going through vacuum is described by vecE=E_(0)sin(kx-wt) and vecB=B_(0)sin(kx-wt) . Which of the following equation is true?

    A
    `E_(0)k=B_(0)omega`
    B
    `E_(0)omega=B_(0)k`
    C
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    D
    `E_(0)omegak=B_(0)`
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