Infra-red rays are :

Options

A. harmful to skin
B. bright red in colour
C. having more energy than ultraviolet rays
D. having less energy as compared to ultraviolet rays

Answer

### Step-by-Step Text Solution:

1. **Understanding Infrared Rays**: Infrared rays are a type of electromagnetic radiation. They fall between visible light and microwaves in the electromagnetic spectrum.

2. **Electromagnetic Spectrum Order**: To understand where infrared rays stand in terms of energy, we can remember the order of electromagnetic waves. The mnemonic "Cute Girls Are Ex-Ultimate Visitors In My Restaurant" can help us remember the sequence:
- C - Cosmic Rays
- G - Gamma Rays
- A - Alpha Rays
- X - X-rays
- U - Ultraviolet Rays
- I - Infrared Rays
- M - Microwaves
- R - Radio Waves

3. **Energy Comparison**: In the electromagnetic spectrum, as we move from cosmic rays to radio waves, the energy of the waves decreases. Since infrared rays are positioned below ultraviolet rays, they have less energy compared to ultraviolet rays.

4. **Analyzing the Options**:
- **Harmful to the Skin**: Infrared rays are generally not harmful to the skin, which makes this option incorrect.
- **Bright Red in Color**: Infrared rays are not visible to the human eye and do not have a specific color, making this option incorrect.
- **More Energy than Ultraviolet Rays**: This is incorrect as we established that infrared rays have less energy than ultraviolet rays.
- **Less Energy than Ultraviolet Rays**: This is the correct option since infrared rays indeed have less energy compared to ultraviolet rays.

5. **Conclusion**: The correct answer is that infrared rays have less energy compared to ultraviolet rays.