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Tarun Krishnan
Subject: Physics
, asked on 21/4/18
30. Write any two advantages of optical fibres over metallic cable in communication.
Answer
1
Tarun Krishnan
Subject: Physics
, asked on 21/4/18
Q
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Answer
1
Tarun Krishnan
Subject: Physics
, asked on 21/4/18
Q 3.
A coin at the bottom Of a beaker 0.1 m deep appears to be raised by 0.03 m when the beaker is filled with a liquid upto its brim. Calculate the R.I. of the liquids.
Answer
1
Mohan
Subject: Physics
, asked on 20/4/18
tricks to solve the ray optics problems in 30 sec
Answer
1
Prerna Varshney
Subject: Physics
, asked on 20/4/18
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Answer
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Aparna Sahu
Subject: Physics
, asked on 20/4/18
Solve this.
36. When a small lamp is held 1.5 m above the surface of water in a tank, its image formed by reflection as the surface appears to coincide with image of the bottom of the tank (
μ
of water = 4/3). The depth of tank is
(a) 2 m
(b) 1.5 m
(c) 1 m
(d) 4 m
Answer
1
Aparna Sahu
Subject: Physics
, asked on 20/4/18
38. A telescope is adjusted for parallel rays. The distance between the objective and the eyepiece is observed to be 20 cm. The magnifying power of the telescope is 9. The focal lengths of the lenses are
a) 11 cm, 9 cm
b) 9 cm, 11 cm
c) 10 cm, 10 cm
d) 18 cm, 2 cm
Answer
1
Muhammad Arafath R Z
Subject: Physics
, asked on 18/4/18
Laws of motion Online 2018 mains
Q.21. A man in a car at location Q on a straight highway is moving with speed v. He decides to reach a point P in a field at a distance d from the highway (point M) as shown in the figure. Speed of the car in the field is half to that on the highway. What should be the distance RM, so that the time taken to reach P is minimum ?
1.
d
3
2.
d
2
3. d
4.
d
2
Answer
1
Muhammad Arafath R Z
Subject: Physics
, asked on 18/4/18
Laws of motion Online 2018 mains
Q.21. A man in a car at location Q on a straight highway is moving with speed v. He decides to reach a point P in a field at a distance d from the highway (point M) as shown in the figure. Speed of the car in the field is half to that on the highway. What should be the distance RM, so that the time taken to reach P is minimum ?
1.
d
3
2.
d
2
3. d
4.
d
2
Answer
1
Aparna Sahu
Subject: Physics
, asked on 18/4/18
Solve 26
Q26. A thin glass prism
μ
=
1
.
5
is immersed in water
μ
=
1
.
3
. If the angle of deviation in air for a particular ray be
δ
, then that in water will be
Answer
1
Aparna Sahu
Subject: Physics
, asked on 18/4/18
Solve qus no. 3:
3. A thin conave and thin convex lenses are in contact. The ratio of the magnitude of power of two lenses is 2/3 and focal length of combination is 30 cm, then the focal lengths of individual lenses are.
(a) 75 cm, 50 cm (b) -75 cm, 50 cm
(b) 75 cm, -50 cm (d) -15 cm, 10 cm
Answer
1
Aparna Sahu
Subject: Physics
, asked on 17/4/18
Solve this:
Solve qus no. 50
Q.50. A convex lens of focal length 30 cm forms an image of height 2 cm for an object situated at infinity. If a concave lens of focal length 20 cm is placed coaxially at a distance of 26 cm in front of convex lens, then size of final image would be
(a) 1.5 cm
(b) 2 cm
(c) 2.5 cm
(d) 4 cm
Answer
1
Aparna Sahu
Subject: Physics
, asked on 16/4/18
Solve qus no. 50
Q.50. A convex lens of focal length 30 cm forms an image of height 2 cm for an object situated at infinity. If a concave lens of focal length 20 cm is placed coaxially at a distance of 26 cm in front of convex lens, then size of final image would be
(a) 1.5 cm
(b) 2 cm
(c) 2.5 cm
(d) 4 cm
Answer
1
Vaishnavi
Subject: Physics
, asked on 15/4/18
A glass sphere (µ = 1.5) of radius 20 cm has a small air bubble 4 cm below its centre. The sphere is viewed from outside and along a vertical line through the bubble. The apparent depth of the bubble below the surface of sphere is (in cm)
(1) 13.33 (2) 26.67 (3) 15 (4) 30
Answer
1
Vaishnavi
Subject: Physics
, asked on 11/4/18
Solve this
34. The critical angle for refraction from glass air is 30
o
and that from water to air is 37
o
. Find the critical angle for refraction from glass to water .
1) sin
-1
(5/6) 2) 51
o
3'
3) 61
o
2 4) 63
o
3'
Answer
1
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What are you looking for?
36. When a small lamp is held 1.5 m above the surface of water in a tank, its image formed by reflection as the surface appears to coincide with image of the bottom of the tank ( of water = 4/3). The depth of tank is
(a) 2 m
(b) 1.5 m
(c) 1 m
(d) 4 m
a) 11 cm, 9 cm
b) 9 cm, 11 cm
c) 10 cm, 10 cm
d) 18 cm, 2 cm
Q.21. A man in a car at location Q on a straight highway is moving with speed v. He decides to reach a point P in a field at a distance d from the highway (point M) as shown in the figure. Speed of the car in the field is half to that on the highway. What should be the distance RM, so that the time taken to reach P is minimum ?
1.
2.
3. d
4.
Q.21. A man in a car at location Q on a straight highway is moving with speed v. He decides to reach a point P in a field at a distance d from the highway (point M) as shown in the figure. Speed of the car in the field is half to that on the highway. What should be the distance RM, so that the time taken to reach P is minimum ?
1.
2.
3. d
4.
Q26. A thin glass prism is immersed in water . If the angle of deviation in air for a particular ray be , then that in water will be
3. A thin conave and thin convex lenses are in contact. The ratio of the magnitude of power of two lenses is 2/3 and focal length of combination is 30 cm, then the focal lengths of individual lenses are.
(a) 75 cm, 50 cm (b) -75 cm, 50 cm
(b) 75 cm, -50 cm (d) -15 cm, 10 cm
Solve qus no. 50
Q.50. A convex lens of focal length 30 cm forms an image of height 2 cm for an object situated at infinity. If a concave lens of focal length 20 cm is placed coaxially at a distance of 26 cm in front of convex lens, then size of final image would be
(a) 1.5 cm
(b) 2 cm
(c) 2.5 cm
(d) 4 cm
Q.50. A convex lens of focal length 30 cm forms an image of height 2 cm for an object situated at infinity. If a concave lens of focal length 20 cm is placed coaxially at a distance of 26 cm in front of convex lens, then size of final image would be
(a) 1.5 cm
(b) 2 cm
(c) 2.5 cm
(d) 4 cm
(1) 13.33 (2) 26.67 (3) 15 (4) 30
34. The critical angle for refraction from glass air is 30o and that from water to air is 37o . Find the critical angle for refraction from glass to water .
1) sin-1(5/6) 2) 51o3'
3) 61o2 4) 63o3'