Choose the correct expression of frequency?

Options

A. `v = c//lambda`
B. `v=c lambda`
C. `v=c+lambda`
D. None of the above

Explanation

To solve the question "Choose the correct expression of frequency," we can follow these steps:

### Step 1: Understand the relationship between velocity, frequency, and wavelength.
The fundamental relationship in wave mechanics is given by the equation:
\[ v = f \lambda \]
where:
- \( v \) is the velocity of the wave,
- \( f \) is the frequency of the wave,
- \( \lambda \) is the wavelength of the wave.

### Step 2: Rearrange the equation to express frequency.
To find the expression for frequency \( f \), we can rearrange the equation:
\[ f = \frac{v}{\lambda} \]

### Step 3: Substitute the velocity of electromagnetic waves.
For electromagnetic waves, the velocity \( v \) is equal to the speed of light \( c \). Therefore, we can substitute \( c \) for \( v \):
\[ f = \frac{c}{\lambda} \]

### Step 4: Analyze the given options.
Now, let's analyze the options provided in the question:
1. \( v = \frac{c}{\lambda} \)
2. \( v = c \lambda \)
3. \( v = c + \lambda \)
4. None of the above.

From our derived equation, we see that the correct expression for frequency is:
\[ f = \frac{c}{\lambda} \]
This means that the first option can be rearranged to express frequency correctly.

### Step 5: Identify the correct option.
The first option \( v = \frac{c}{\lambda} \) is a correct expression for the velocity of electromagnetic waves in terms of wavelength. Thus, it implies that frequency can be expressed as:
\[ f = \frac{c}{\lambda} \]

Therefore, the correct answer is:
**Option 1: \( v = \frac{c}{\lambda} \)**

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