Refraction, Glass Slab & Apparent Depth
As shown in the figure, a plane mirror is fixed at a height of from the bottom of tank containing water . The height of water in the tank is . A small bulb is placed at the bottom of the water tank. The distance of image of the bulb formed by mirror from the bottom of the tank is ___________ .

Numerical answer type. Work it out, then open the answer.
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Answer: 98
- The bulb seen from above appears at depth below the water surface, i.e. above the bottom.
- This apparent bulb is the object for the mirror: distance from mirror .
- Plane mirror image is behind (above) the mirror: from the bottom.
- So the image is from the bottom.