Which of the following is Bragg's equation ?

Options

A. `nlambda=2thetasintheta`
B. `nlambda=2 d sin theta`
C. `2nlambda=d sin theta`
D. `n.theta//2=d//2sintheta`

Explanation

To solve the question regarding Bragg's equation, we need to identify the correct formula that represents it. Here’s a step-by-step breakdown:

### Step 1: Understanding Bragg's Law
Bragg's Law relates the wavelength of electromagnetic radiation to the diffraction angle and the spacing between crystal planes. It is fundamental in the study of crystal structures using X-ray diffraction.

### Step 2: Identifying the Components of Bragg's Equation
Bragg's equation is typically expressed as:
\[ n \lambda = 2d \sin \theta \]
Where:
- \( n \) = an integer (order of reflection)
- \( \lambda \) = wavelength of the incident light
- \( d \) = distance between the crystal planes
- \( \theta \) = angle of incidence (and reflection)

### Step 3: Analyzing the Given Options
If provided with multiple choices, we need to look for the equation that matches the form of Bragg's Law stated above. The correct option will include the terms \( n \), \( \lambda \), \( d \), and \( \theta \) in the appropriate arrangement.

### Step 4: Conclusion
The correct Bragg's equation is:
\[ n \lambda = 2d \sin \theta \]

### Final Answer
The correct answer is:
**Bragg's equation is \( n \lambda = 2d \sin \theta \).**