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It consists of three cases followed by questions. There are a total of 12 questions (Q. No. 49 to 60 ) in this section. Attempt any 10 questions from this section. The first attempted 10 questions would be evaluated. P-Did not react eiter with cold or hot water but reacted with steam
Q- Reacted with hot water and the metal started floating
R - Reacted violently with cold water
S- Did not react with water at all
Based on the above observation answer the following:
Case-I:
A student, took four metalsP , Q , R
- All metal could not be cut with knife except metal R.
- Metal P combined with oxygen to form an oxideM 2 O 3
- Reaction with water.
Q- Reacted with hot water and the metal started floating
R - Reacted violently with cold water
S- Did not react with water at all
Based on the above observation answer the following:
Case-I:
A student, took four metals
- All metal could not be cut with knife except metal R.
- Metal P combined with oxygen to form an oxide
- Reaction with water.
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Question : 60
Total: 60
If power of the eyepiece ( L 2 ) 80 cm
Solution:
Explanation: The relation between focal length and power of a lens is:
f = 1 ∕ P P f
⇒ f = 1 ∕ 5 m
⇒ f = 0.2 m
⇒ f = 20 cm
Since focal lens is positive, therefore it is a convex lens. In a convex lens, image formed is virtual when the object distance is less than the focal length.
Here, option (d) cannot be the answer because if object distance= 20 cm 20 cm 80 cm
Therefore, according to sign conventions:
v = − 80 cm
For finding the object distance, the lens formula is used. The lens formula is:
=
−
⇒
=
−
⇒
=
−
⇒
=
⇒
=
⇒
=
⇒ u = − 16 cm
Since focal lens is positive, therefore it is a convex lens. In a convex lens, image formed is virtual when the object distance is less than the focal length.
Here, option (d) cannot be the answer because if object distance
Therefore, according to sign conventions:
For finding the object distance, the lens formula is used. The lens formula is:
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