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Raghav Singh
Subject: Science
, asked on 25/2/18
Please solve question 47.
Q.47. What is the focal length of a mirror? Consider the following set up given below and determine the focal length of concave mirror.
Answer
1
L.vibha
Subject: Science
, asked on 25/2/18
What are the main questions that can come from 'Light- Reflection and Refraction'?
Answer
1
Harsh
Subject: Science
, asked on 24/2/18
A convex lens of focal length 20 cm produces 3 times magnified real image of an object. find the position of the object.
Answer
1
Harsh
Subject: Science
, asked on 24/2/18
Answer question 4 with proper steps.
Q-4) The power of a combination of two lenses XY is 5D if the focal length of the lens X is 15 cm. State the nature and focal length of lens Y.
Answer
1
Raghav Singh
Subject: Science
, asked on 24/2/18
Please tell about the calculation part after finding r=0.42 , i cant understand how...?
Answer
3
Raghav Singh
Subject: Science
, asked on 24/2/18
Please answer this q.
Q.10. The refractive index of water is 1.33 and the speed of light in air is
$3\times {10}^{8}m{s}^{-1}$
. Calculate the speed of light in water.
Answer
3
Raghav Singh
Subject: Science
, asked on 24/2/18
If an object is held at a distance of 60 cm from a convex mirror of focal length 20 cm. At what distance from the convex mirror, should a plane mirror be held, so that images in the two mirrors coincide?
Answer
1
Raghav Singh
Subject: Science
, asked on 24/2/18
When an object is placed at a distance of 60 cm from a convex spherical mirror, the magnification produced is
$\frac{1}{2}$
. Where should the object be placed to get a magnification of
$\frac{1}{3}$
?
Answer
1
Raghav Singh
Subject: Science
, asked on 24/2/18
(ii) If the refractive index of glass for light going from air to glass is 3/2, find the refractive index of air for light going from glass to air.
Answer
1
Champ Jee
Subject: Science
, asked on 24/2/18
Solve this :
23. A student performed an experiment to trace te path of a ray of light passing through a rectangular glass slab for different angles of incidence. His observations are given below :
Observation set No.
I
II
III
IV
V
VI
Angle of incidence - i
30
^{o}
35
^{o}
40
^{o}
45
^{o}
50
^{o}
55
^{o}
Angle of refraction - r
19
^{o}
23
^{o}
26
^{o}
28
^{o}
42
^{o}
34
^{o}
Angle of refraction - e
30
^{o}
36
^{o}
41
^{o}
45
^{o}
54
^{o}
56
^{o}
One observation set out of these is wrong. Which set is wrong and why ?
Answer
2
Raghav Singh
Subject: Science
, asked on 23/2/18
What is frequency ? Please tell about the frequency of light.
Answer
1
Champ Jee
Subject: Science
, asked on 23/2/18
Is this in series or parallel.
(THIS IS DIFFERENT FROM PERVIOYSLY ASKED)...
Answer
7
Romil Singh
Subject: Science
, asked on 23/2/18
give the reason for Shallow appearance of swimming pool
Answer
1
Champ Jee
Subject: Science
, asked on 23/2/18
Q43.
(Ans : focal length = +2.81 cm)
Answer
1
Sneha Jain
Subject: Science
, asked on 23/2/18
5qies
Answer
1
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Q.47. What is the focal length of a mirror? Consider the following set up given below and determine the focal length of concave mirror.

What are the main questions that can come from 'Light- Reflection and Refraction'?Q-4) The power of a combination of two lenses XY is 5D if the focal length of the lens X is 15 cm. State the nature and focal length of lens Y.

Q.10. The refractive index of water is 1.33 and the speed of light in air is $3\times {10}^{8}m{s}^{-1}$. Calculate the speed of light in water.

Solve this :23. A student performed an experiment to trace te path of a ray of light passing through a rectangular glass slab for different angles of incidence. His observations are given below :

^{o}^{o}^{o}^{o}^{o}^{o}^{o}^{o}^{o}^{o}^{o}^{o}^{o}^{o}^{o}^{o}^{o}^{o}(THIS IS DIFFERENT FROM PERVIOYSLY ASKED)...

(Ans : focal length = +2.81 cm)