Rectangular And Circular Waveguides

Step 1: Recall the formula for apparent depth.

The apparent depth ( ) is related to the real depth ( ) and the refractive index ( ) of the medium by the formula:

Step 2: Substitute the given values.

The real depth of the tank is , and the refractive index of water is . Substituting these values:

Final Answer: The bottom of the tank appears to be at a depth of , which corresponds to option .