The heat from the sun reaches us on the earth by the process of :

Options

A. conduction
B. radiation
C. convection
D. none of these

Answer

To solve the question "The heat from the sun reaches us on the earth by the process of:", we will analyze the different methods of heat transfer and determine the correct one.

### Step-by-Step Solution:

1. **Understanding Heat Transfer Methods**:
- There are three main methods of heat transfer: conduction, convection, and radiation.
- **Conduction**: This is the transfer of heat through a solid material, where heat moves from the hotter part of the material to the cooler part. This process requires direct contact between materials.
- **Convection**: This is the transfer of heat through fluids (liquids and gases) where warmer parts of the fluid rise and cooler parts sink, creating a circulation pattern. This process also requires a medium (fluid) for heat transfer.

2. **Analyzing the Environment Between the Sun and Earth**:
- The space between the Sun and the Earth is a vacuum, which means there are no particles or medium present.
- Since conduction and convection require a medium to transfer heat, they cannot occur in a vacuum.

3. **Identifying the Correct Process**:
- **Radiation**: This is the process of heat transfer through electromagnetic waves. Unlike conduction and convection, radiation does not require a medium and can occur in a vacuum.
- The energy from the Sun travels through space in the form of electromagnetic waves (including visible light, infrared radiation, etc.) and reaches the Earth.

4. **Conclusion**:
- The heat from the Sun reaches us on Earth by the process of **radiation**.

### Final Answer:
The heat from the sun reaches us on the earth by the process of **radiation**.

---