Green house effect is to

Options

A. transmit radiations from a source at high temperature and block radiations from a source at low temperature.
B. transmit radiations from a source at low temperature and block radiations from source at high temperature.
C. transmit radiations from both the types of sources.
D. block radiations from both the types of sources at high and low temperature.

Answer

To solve the question about the greenhouse effect, we need to understand the concept and then analyze the provided options. Here’s a step-by-step breakdown:

### Step 1: Understand the Greenhouse Effect
The greenhouse effect is a natural process where certain gases in the Earth's atmosphere trap heat. This occurs when the sun emits radiation, which passes through the atmosphere and warms the Earth's surface. The Earth then emits this heat in the form of infrared radiation. However, greenhouse gases like carbon dioxide (CO2) and methane (CH4) absorb some of this infrared radiation and re-radiate it back towards the Earth, preventing it from escaping into space. This leads to an increase in the Earth's temperature.

### Step 2: Analyze the Options
Now, we will evaluate each option based on our understanding of the greenhouse effect.

1. **Option 1**: "Greenhouse effect is to transmit radiation from the source at a higher temperature and block radiation from the source at low temperature."
- This option is **correct**. The greenhouse effect allows radiation from the sun (higher temperature) to enter the Earth but traps the heat radiated by the Earth (lower temperature).

2. **Option 2**: "Transmit radiation from source at lower temperature."
- This option is **incorrect**. The greenhouse effect does not transmit radiation from a lower temperature to a higher temperature spontaneously.

3. **Option 3**: "Transmit radiation from both types of sources."
- This option is **incorrect**. While it is possible to transfer heat from a lower temperature to a higher temperature, it cannot happen spontaneously without work. The greenhouse effect specifically involves the trapping of heat emitted from a lower temperature body (Earth) by higher temperature gases.

4. **Option 4**: "Block radiation from both types of sources at high and low temperature."
- This option is **incorrect**. The greenhouse effect does not block radiation from high temperature sources (like the sun); it allows that radiation to enter while blocking some of the radiation from the lower temperature source (Earth).

### Conclusion
Based on the analysis, the correct answer is **Option 1**.

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