An EMW is travelling along z-axis `vecB=5 xx 10^(-8) hatj T`, `C=3 xx 10^8 m/s` & Frequency of wave is 25 Hz, then electric field in volt/m.

Explanation

To find the electric field (E) of an electromagnetic wave given the magnetic field (B), speed of light (C), and frequency, we can follow these steps:

### Step 1: Understand the relationship between E and B
The relationship between the electric field (E) and the magnetic field (B) in an electromagnetic wave is given by the equation:
\[ \frac{E_0}{B_0} = c \]
where \(E_0\) is the amplitude of the electric field, \(B_0\) is the amplitude of the magnetic field, and \(c\) is the speed of light in vacuum.

### Step 2: Identify the given values
From the problem, we have:
- \(B_0 = 5 \times 10^{-8} \, \text{T}\) (Tesla)
- \(c = 3 \times 10^8 \, \text{m/s}\)

### Step 3: Rearrange the equation to solve for E
We can rearrange the equation to solve for the electric field \(E_0\):
\[ E_0 = c \cdot B_0 \]

### Step 4: Substitute the known values
Now, substitute the values of \(c\) and \(B_0\) into the equation:
\[ E_0 = (3 \times 10^8 \, \text{m/s}) \cdot (5 \times 10^{-8} \, \text{T}) \]

### Step 5: Perform the multiplication
Calculating this gives:
\[ E_0 = 3 \times 5 \times 10^8 \times 10^{-8} = 15 \, \text{V/m} \]

### Step 6: State the final answer
Thus, the electric field \(E_0\) is:
\[ E_0 = 15 \, \text{V/m} \]