What is the principle on which SONAR is based ?

Explanation

**Step-by-Step Solution:**

1. **Understanding SONAR**: SONAR stands for Sound, Navigation, and Ranging. It is a technique used to determine the distance to an object underwater, such as the ocean bed.

2. **Principle of Operation**: SONAR operates on the principle of sound wave reflection. When a sound wave is emitted from a transmitter, it travels through the water until it hits an object (like the ocean bed) and reflects back to the source.

3. **Distance Calculation**: The distance to the object is calculated using the formula:
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