NCERT Solutions
Board Paper Solutions
Ask & Answer
School Talk
Login
GET APP
Login
Create Account
Popular
Latest
Shubhrajyoti Ghosh
Subject: Physics
, asked on 16/3/18
No links please
Q. State Huygen's principle. If white light is used in place of monochromatic light in Young's double slit experiment, what change will be observed in the interference pattern? What are the conditions for two sources being 'Coherent'?
Answer
1
Shubhrajyoti Ghosh
Subject: Physics
, asked on 15/3/18
No links please
Q. The interior of a hollow metal sphere is polished to serve as a mirror. At a point 12 cm from the centre of the sphere of radius 24 cm, a point source of light is placed. Locate its image formed by two successive reflections, the first reflection taking place at the (a) far wall (b) near wall.
Answer
1
Shubhrajyoti Ghosh
Subject: Physics
, asked on 15/3/18
No links please
Q. An image produced by a concave mirror is one-fourth the size of the object. If the object is moved 10 cm towards the mirror, its image will be only half the size of the object. Calculate the focal length of the mirror.
Answer
1
Shubhrajyoti Ghosh
Subject: Physics
, asked on 15/3/18
No links please
Q. The interior of a hollow metal sphere is polished to serve as a mirror. At a point 12 cm from the centre of the sphere of radius 24 cm, a point source of light is placed. Locate its image formed by two successive reflections, the first reflection taking place at the (a) far wall (b) near wall.
Answer
1
Shubhrajyoti Ghosh
Subject: Physics
, asked on 15/3/18
A ray of light of wave length 6000
A
ο
falls on a metal plate. To drag electron from the metal 1.77 ev energy is required.Find the maximum energy of the emitting electron and the threshold frequency of the metal. [Given Plank's constant 'h' = 6.6 x 10
-27
erg-sec]
Answer
1
Shubhrajyoti Ghosh
Subject: Physics
, asked on 15/3/18
Q. Two spherical mirrors - one convex and the other concave, are each of the same radius r. They are arranged coaxially at a distance 2r from each other. A small circle of radius a is drawn on the convex mirror near the pole. Prove that the radii of the first two images are a/3 and a/ 11.
Answer
1
Shubhrajyoti Ghosh
Subject: Physics
, asked on 15/3/18
No links please
Q. What do you mean by polarisation of light.
Compare between interference and diffraction. Establish Brewster's law.
Answer
1
Shubhrajyoti Ghosh
Subject: Physics
, asked on 15/3/18
No links please:
Q. A compound microscope consists of two lenses of focal lengths 0.8 cm and 3 cm respectively. If the object is 0.85 cm from the objective and the final image is to be 24 cm from the eye-piece, compute the magnifying power of the microscope.
A shot sighted person cannot see distinctly objects beyond 2m from the eye. Find the focal length and the powe rof the spectacle lens which will enable him to see distant objects clearly.
Answer
1
Shubhrajyoti Ghosh
Subject: Physics
, asked on 15/3/18
No links please
(b)
An object is D cm from a screen. A convex lens forms an image of it on the screen. When moved through a distance x cm, it forms another image. Prove that the ratio of the sizes of the two images produced is
D
+
X
D
-
X
2
.
Answer
2
Shubhrajyoti Ghosh
Subject: Physics
, asked on 15/3/18
No links please
Q. State Huygen's principle. In the light of Huygen's principle, explain the refraction of light.
Answer
1
Shubhrajyoti Ghosh
Subject: Physics
, asked on 15/3/18
No links please
Q.(b) A man can read a newspaper clearly which is placed at a distance 25 cm from the eye with the help of a spectacle of power + 3D. If he wants to read it without spectacle then how far he has to place the newspaper from his eye?
Answer
2
Shubhrajyoti Ghosh
Subject: Physics
, asked on 14/3/18
(c)
In an aquarium, a fish 6 cm long is swimming directly towards the plane glass front. If, at a certain moment, head of the fish is 18 cm behind the glass front, find the apparent length of the fish as seen by a person looking through the glass. Given R.I. of water =4/3.
Answer
1
Shubhrajyoti Ghosh
Subject: Physics
, asked on 14/3/18
No links please:
(b) The focal length of a glass lens in air is 5 cm. What will be its focal length in water ?
μ
g
=
1
.
51
,
μ
w
=
1
.
33
Answer
2
Shubhrajyoti Ghosh
Subject: Physics
, asked on 14/3/18
(b) An object is D cm from a screen. A convex lens forms an image of it on the screen. When moved through a distance x cm, it forms another image. Prove that the ratio of the sizes of the two images produced is
D
+
x
D
-
x
2
[2 + 3]
Answer
1
Shubhrajyoti Ghosh
Subject: Physics
, asked on 14/3/18
No links please
Q. Find the focal length of the projector-lens which projects the image of size 60
×
60 cm of a slide on a screen 2.4 m away, the slide being of the size 3
×
3 cm.
Light enters a prism of angle A at a grazing incidence to emerge at an angle
θ
with the normal. Show that the refractive index of the material of the prism is given by,
μ
=
1
+
cos
A
+
sin
θ
sin
A
2
1
2
Answer
1
Prev
3
4
5
6
7
Next
What are you looking for?
Q. State Huygen's principle. If white light is used in place of monochromatic light in Young's double slit experiment, what change will be observed in the interference pattern? What are the conditions for two sources being 'Coherent'?
Q. The interior of a hollow metal sphere is polished to serve as a mirror. At a point 12 cm from the centre of the sphere of radius 24 cm, a point source of light is placed. Locate its image formed by two successive reflections, the first reflection taking place at the (a) far wall (b) near wall.
Q. An image produced by a concave mirror is one-fourth the size of the object. If the object is moved 10 cm towards the mirror, its image will be only half the size of the object. Calculate the focal length of the mirror.
Q. The interior of a hollow metal sphere is polished to serve as a mirror. At a point 12 cm from the centre of the sphere of radius 24 cm, a point source of light is placed. Locate its image formed by two successive reflections, the first reflection taking place at the (a) far wall (b) near wall.
Q. What do you mean by polarisation of light.
Compare between interference and diffraction. Establish Brewster's law.
Q. A compound microscope consists of two lenses of focal lengths 0.8 cm and 3 cm respectively. If the object is 0.85 cm from the objective and the final image is to be 24 cm from the eye-piece, compute the magnifying power of the microscope.
A shot sighted person cannot see distinctly objects beyond 2m from the eye. Find the focal length and the powe rof the spectacle lens which will enable him to see distant objects clearly.
(b) An object is D cm from a screen. A convex lens forms an image of it on the screen. When moved through a distance x cm, it forms another image. Prove that the ratio of the sizes of the two images produced is
Q. State Huygen's principle. In the light of Huygen's principle, explain the refraction of light.
Q.(b) A man can read a newspaper clearly which is placed at a distance 25 cm from the eye with the help of a spectacle of power + 3D. If he wants to read it without spectacle then how far he has to place the newspaper from his eye?
(b) The focal length of a glass lens in air is 5 cm. What will be its focal length in water ?
Q. Find the focal length of the projector-lens which projects the image of size 6060 cm of a slide on a screen 2.4 m away, the slide being of the size 33 cm.
Light enters a prism of angle A at a grazing incidence to emerge at an angle with the normal. Show that the refractive index of the material of the prism is given by,