Light has the following wave property

Options

A. Laser light always lies in the X - ray region
B. Laser light does not have directionality property
C. Laser light is white light
D. Laser light is highly coherent

Answer

To solve the question regarding the wave properties of laser light, we can analyze the statements provided one by one.

### Step-by-Step Solution:

1. **Examine Statement A**: "Laser light always lies in the X region."
- This statement is incorrect. Laser light can have wavelengths that range from approximately 180 nanometers (in the ultraviolet range) to about 700 nanometers (in the visible range). Therefore, laser light is not confined to a single region but spans multiple regions of the electromagnetic spectrum.

2. **Examine Statement B**: "Laser does not have a directional property."
- This statement is also incorrect. One of the defining characteristics of laser light is its highly directional nature. Laser beams are collimated, meaning they travel in parallel rays and maintain their intensity over long distances, which is a significant property of laser light.

3. **Examine Statement C**: "Laser is a white light."
- This statement is incorrect. Laser light is typically monochromatic, meaning it consists of a single wavelength or color. In contrast, white light is a combination of multiple wavelengths (colors), such as red, orange, yellow, green, blue, indigo, and violet (VIBGYOR). Therefore, this statement is false.

4. **Examine Statement D**: "Laser light is highly coherent."
- This statement is correct. Coherence refers to the phase relationship between the waves. Laser light is characterized by its high degree of coherence, meaning that the waves are in phase with each other. This property allows laser light to maintain its intensity and focus over long distances, making it suitable for various applications.

### Conclusion:
Based on the analysis, the correct statement regarding the wave properties of laser light is:
- **D: Laser light is highly coherent.**