_________is mainly used in submarines to view objects present above the surface of water.

Options

A. Periscope
B. Kaleidoscope
C. Plane mirror
D. All of them

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for a device that is used in submarines to view objects above the surface of the water.

2. **Identifying the Options**: The options provided include various optical instruments. Among them, we need to identify which one is specifically used in submarines.

3. **Analyzing the First Option - Periscope**: A periscope is a device that allows a person to see objects that are not in their direct line of sight. It typically consists of a long tube with mirrors at each end set at an angle, allowing light to reflect down the tube.

4. **Function of a Periscope in Submarines**: In submarines, a periscope is used to observe the surface of the water while remaining submerged. The mirrors reflect the light from the surface down into the submarine, allowing the crew to see above the water without exposing the submarine.

5. **Conclusion**: Since the periscope is specifically designed for this purpose, it is the correct answer to the question.

6. **Final Answer**: The device mainly used in submarines to view objects present above the surface of water is called a **Periscope**.

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