Recent questions in Physics

0 votes

0 answers

Light incident at an angle of incidence of 45° in a certain medium goes grazing along its surface of separation from air after refraction. What is (i) the velocity of light in this medium? (ii) the angle of incidence at which light from air must be incident on this medium so that the refracted ray is normal to the reflected ray? Also, name the special property exhibited by light for this angle of

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

0 votes

0 answers

One day Chetan's mother developed a severe stomach ache all of a sudden. She was rushed to the doctor who suggested for an immediate endoscopy test and gave an estimate of expenditure for the same. Chetan immediately contacted his class teacher and shared the information with her. The class teacher arranged for the money and rushed to the hospital. On realising that Chetan belonged to a below average income group family, even the doctor offered concession for the test fee. The test was conducted successfully. Answer the following questions based on the above information. (i) Which principle in optics is

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

0 votes

0 answers

(i) A point object O is kept in a medium of refractive index in front of a convex spherical surface of radius of curvature R which separates the second medium of refractive index `n_2` from the first one, as shown in the figure.Draw the ray diagram showing the image formation and deduce the relationship between the object distance and the image distance in terms of `n_1 , n_2 and R`.(ii) When the image formed above acts as a virtual object for a concave spherical surface separating the medium `n_2` from `n_1(n_2 > n_1)` , draw this ray diagram and write

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

0 votes

0 answers

(i) A ray PQ of light is incident on the face AB of a glass prism ABC (as shown in the figure) and emerges out of the face AC. Trace the path of the ray. Show that `/_i+/_e=/_A+/_delta` where, `delta` and e denote the angle of deviation and angle of emergence respectively. Plot a graph showing the variation of the angle of deviation as a function of angle of incidence. State the condition under which `/_delta` is minimum. (ii) Find out the relation between the refractive index `(mu)` of the glass prism and `/_A` for the case, when the angle

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

0 votes

0 answers

(i) A point object is placed in front of a double convex lens (or refractive index `mu=n_2/n_1` with respect to air) with its spherical faces of radii of curvature `R_1 and R_2` Show the path of rays due to refraction at first and subsequently at the second surface to obtain the formation of the real image of the object. Hence, obtain the lens maker's formula for a thin lens. (ii) A double convex lens having both faces of the same radius of curvature has refractive index 1.55. Find out the radius of curvature of the lens required to get the

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

0 votes

0 answers

Draw a ray diagram showing the formation of the image by a point object on the principal axis of a spherical convex surface separating two media of refractive indices `n_1 and n_2`, when a point source is kept in rarer medium of refractive index `n_1`. Derive the relation between object and image distance in terms of refractive index of the medium and radius of curvature of the surface. Hence, obtain the expression for lens maker's formula in the case of thin convex

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

0 votes

0 answers

(i) Draw a ray diagram to show refraction of a ray of monochromatic light passing through a glass prism. Deduce the expression for the refractive index of glass in terms of angle of prism and angle of minimum deviation, (ii) Explain briefly how the phenomenon of total internal reflection is used in fibre

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

0 votes

0 answers

(i) Obtain lens maker's formula using the expression`n_2/v-n_1/u=((n_2-n_1))/R`Here, the ray of light propagating from a rarer medium of refractive index `(n_1)` to a denser medium of refractive index `(n_2)` is incident on the convex side of spherical refracting surface of radius of curvature R. (ii) Draw a ray diagram to show that image formation by a concave mirror when the object is kept between its focus and the pole. Using this diagram, derive the magnification formula for the image

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

0 votes

0 answers

(i) Figure shows a convex spherical surface with centre of curvature C separating the two media of refractive indices `n_1 and n_2`. Draw a ray diagram showing the formation of the image of a point object O lying on the principal axis. Derive the relationship between the object and image distance in terms of refractive indices of the media and the radius of curvature R of the surface. (ii) Define the magnifying power of a compound microscope. Why should both the objective and the eyepiece have small focal lengths in a

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

0 votes

0 answers

Trace the rays of light showing the formation of an image due to a point object placed on the axis of a spherical surface separating the two media of refractive indices `n_1 and n_2`. Establish the relation between the distance of the object, the distance of image and the radius of curvature from the central point of the spherical surface. Hence, derive the expression of the lens maker's

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

0 votes

0 answers

(i) Draw a ray diagram for formation of image of a point object by a thin double convex lens having radii of curvatures `R_1 and R_2` and hence, derive lens maker's formula. (ii) Define power of a lens and give its SI unit. If a convex lens of length 50 cm is placed in contact coaxially with a concave lens of focal length 20 cm, what is the power of the

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

0 votes

0 answers

(i) Draw the ray diagram for the formation of image of an object by a convex mirror and use it (along with the sign convention) to derive the mirror formula. (ii) Use the mirror formula to show that for an object kept between the pole and focus of a concave mirror the image appears to be formed behind the

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

0 votes

0 answers

Draw a ray diagram of a reflecting type telescope. State two advantages of this telescope over a refracting

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

0 votes

0 answers

Draw a schematic diagram of refracting telescope. Write its two important

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

0 votes

0 answers

Draw a ray diagram for the formation of image by a compound microscope. Write the expression for total magnification when the image is formed at

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

0 votes

0 answers

A convex lens of focal length 25 cm is placed coaxially in contact with a concave lens of focal length 20 cm. Determine the power of the combination. Will the system be converging or diverging in

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

0 votes

0 answers

Draw a schematic arrangement of a reflecting telescope (Cassegrain) showing how rays coming from a distant object are received at the eyepiece. Write its two important advantages over a refracting

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

0 votes

0 answers

Two convex lenses of same focal length but of apertures `A_1 and A_2 (A_2 < A_1)`, are used as the objective lenses in two astronomical telescopes having identical eyepieces. What is the ratio of their resolving power? Which telescope will you prefer and why? Give

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

0 votes

0 answers

Define the resolving power of a telescope. Write any two advantages of a reflecting telescope over a refracting

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

0 votes

0 answers

(i) A giant refracting telescope has an objective lens of focal length 15 m. If an eyepiece of focal length 1.0 cm is used, what is the angular magnification of the telescope? (ii) If this telescope is used to view the moon, what is the diameter of the image of the moon formed by the objective lens? The diameter of the moon is `3.48xx10^6` m and the radius of lunar orbit is `3 .8xx10^8

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

Recent questions in Physics

Categories