Advertisements
Advertisements
Questions
A straight stick partly dipped in water obliquely appears to be bent at the surface of the water.
A rod immersed partially and obliquely in water appears to be bent. Explain.
Advertisements
Solution 1
The phenomenon is due to refraction of light.
A ray of light OC coming from O passes from water into air and is refracted away from normal (along CX). Another ray, OD, gets refracted along with DY. The two refracted rays CX and DY, when produced backwards, appear to meet at the point I. Thus, I is the virtual image of the end O of the stick. Therefore, the stick appears to be bent as shown below.
Solution 2
- Light Refraction: When light passes from one medium (e.g., water) to another (e.g., air), it changes speed and direction. Light rays traveling from the submerged part of the stick (in water) to the observer's eyes (in air) bend away from normal at the water’s surface.
- Apparent Bending: Due to this bending of light, the part of the stick underwater appears shifted upward. As a result, the stick seems bent at the surface of the water, even though it is straight.
APPEARS IN
RELATED QUESTIONS
A simple microscope is used by watch repairers. Give reason.
Explain the following term related to spherical lenses:- optical centre
An image that cannot be obtained on a screen is called ______.
Give one use each of a concave and a convex mirror.
A 50 cm tall object is at a very large distance from a diverging lens. A virtual, erect and diminished image of the object is formed at a distance of 20 cm in front of the lens. How much is the focal length of the lens?
Write true or false
A virtual image formed by a spherical mirror is always erect and situated behind the mirror.
State the number of images of an object placed between two mirrors, formed in each case when mirrors are inclined to each other at (a) 90°, and (b) 60°.
Define the terms focus and focal length of a concave mirror. Draw diagram to illustrate your answer.
Name the mirror which always produces an erect and virtual image. How is the size of image related to the size of object?
Discuss the position and nature of image formed by a concave mirror when an object is moved from infinity towards the pole of mirror.
The radius of curvature of a convex mirror is 40 cm. Find its focal length.
A point light source is kept in front of a convex mirror at a distance of 40 cm. The focal length of the mirror is 40 cm. Find the position of image.
Find the height of the image of a body of height 1.5m in a mirror with a magnification of 1.5.
What is the relationship between the focal length and radius of curvature?
Define the term Principle focus.
Complete the following diagrams shown in the following figures by drawing the reflected rays.
