Understanding Solar Radiation Types

Solar radiation is energy that travels from the sun to the Earth. This energy reaches us in different forms depending on how it interacts with the Earth's atmosphere. The question asks specifically about solar radiations received directly from the sun without any change in direction.

Types of Solar Radiation Explained

Let's break down the different types of solar radiation mentioned:

• Beam Radiation: This is the direct solar radiation that travels in a straight line from the sun to the Earth's surface. It doesn't get scattered or reflected by the atmosphere. When the sun is shining directly on a surface, like a solar panel, it's receiving beam radiation. This type of radiation is also known as direct normal irradiance (DNI) when measured perpendicular to the sun's rays.
• Diffused Radiation: This is solar radiation that has been scattered by atmospheric components like clouds, dust particles, and gases. It doesn't travel in a straight line from the sun. Diffused radiation comes from all directions in the sky. Even on a cloudy day, we still receive diffused radiation.
• Global Radiation: This is the total amount of solar radiation received on a horizontal surface. It's the sum of both the direct beam radiation and the diffused radiation. On a clear day, beam radiation makes up the larger part of global radiation, while on a cloudy day, diffused radiation is the dominant component.

Identifying Radiation Without Direction Change

Based on the definitions:

• Beam radiation travels directly from the sun without its path being altered.
• Diffused radiation has been scattered, meaning its direction has changed.
• Global radiation is the total, including both direct and scattered radiation.

Therefore, the solar radiations received from the sun without change of direction are specifically called Beam radiation.

Correct Option Analysis

The question asks for solar radiation received without a change in direction. This matches the definition of Beam radiation.

• Option 1 (Diffused radiation) is incorrect because this radiation is scattered and changes direction.
• Option 2 (Beam radiation) is correct as it represents the direct, unaltered path of solar energy from the sun.
• Option 3 (Global radiation) is incorrect because it includes both direct and diffused radiation; it's the total received, not just the part without direction change.