Advertisements
Advertisements
प्रश्न
A point object O is placed at a distance of 15cm from a convex lens L of focal length 1 Ocm as shown in Figure 5 below. On the other side of the lens, a convex mirror M is placed such that its distance from the lens is equal to the focal length of the lens. The final image formed by this combination is observed to coincide with the object O. Find the focal length of the convex mirror
उत्तर
u = 15 cm
f = 10 cm
d = f = 10 cm
For lens, `1/V - 1/u = 1/f`
`1/V - 1/((-15)) = 1/10`
`1/V = 1/10 -= 1/15 = (3-2)/30 = 1/30`
V= 30 cm
MI = LI - LM = 30 - 10 = 20 cm
`f = 20/2 = 10 cm`
APPEARS IN
संबंधित प्रश्न
Use the mirror equation to deduce that the virtual image produced by a convex mirror is always diminished in size and is located between the focus and the pole.
Use the mirror equation to deduce that an object placed between the pole and focus of a concave mirror produces a virtual and enlarged image.
Using mirror formula, explain why does a convex mirror always produce a virtual image.
A cylindrical vessel of diameter 12 cm contains 800π cm3 of water. A cylindrical glass piece of diameter 8.0 cm and height 8.0 cm is placed in the vessel. If the bottom of the vessel under the glass piece is seen by the paraxial rays (see figure), locate its image. The index of refraction of glass is 1.50 and that of water is 1.33.
A small object is placed at the centre of the bottom of a cylindrical vessel of radius 3 cm and height 4 cm filled completely with water. Consider the ray leaving the vessel through a corner. Suppose this ray and the ray along the axis of the vessel are used to trace the image. Find the apparent depth of the image and the ratio of real depth to the apparent depth under the assumptions taken. Refractive index of water = 1.33.
A light ray, going through a prism with the angle of prism 60°, is found to deviate by 30°. What limit on the refractive index can be put from these data?
Name the physical principle on which the working of optical fibers is based.
The focal length f is related to the radius of curvature r of the spherical convex mirror by ______.
Car B overtakes car A at a relative speed of 40 ms-1. How fast will the image of car B appear to move in the mirror of focal length 10 cm fitted in car A, when car B is 1.9 m away from car A?
A convex lens of focal length 15 cm is placed coaxially in front of a convex mirror. The lens is 5 cm from the pole of the mirror. When an object is placed on the axis at a distance of 20 cm from the lens, it is found that the image coincides with the object. Calculate the radius of curvature of the mirror - (consider all-optical event):
