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Question
The diagram below shows a lens as a combination of a glass slab and two prisms.
- Name the lens formed by the combination.
- What is the line XX’ called?
- Complete the path of the incident ray AB after passing through the lens.
- The final emergent ray either meets XX’ at a point or appears to come from a point on XX’. Label it as F. What is this point called?
Solution
- The combination forms a concave lens.
- XX' is known as the principal axis.
- complete diagram is drawn as
- The point F is called a focal point or focus.
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