Red drop occurs in wavelength of

Options

A. 492 nm
B. 535 nm
C. 586 nm
D. 680 nm.

Answer

**Step-by-Step Solution:**

1. **Understanding the Red Drop Effect**: The red drop effect refers to a phenomenon in photosynthesis where there is a significant decrease in the quantum yield of photosynthesis at certain wavelengths of light.

2. **Defining Quantum Yield**: Quantum yield is defined as the number of molecules of oxygen released per quantum (or photon) of light absorbed. It is a measure of the efficiency of photosynthesis.

3. **Identifying the Wavelengths**: The question provides four options for wavelengths: 492 nm, 335 nm, 586 nm, and 680 nm.

4. **Analyzing the Red Drop Effect**: The red drop effect is specifically noted to occur at wavelengths greater than 680 nm. This means that as the wavelength increases beyond this point, the efficiency of photosynthesis decreases sharply.

5. **Selecting the Correct Option**: Since the red drop effect occurs at wavelengths greater than 680 nm, the correct answer from the options provided is 680 nm itself.

6. **Final Answer**: Therefore, the red drop occurs at a wavelength of **680 nm**.

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