Advertisements
Advertisements
Question
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.
Advertisements
Solution
Given,
u = 40 cm (negative)
f = 40 cm (positive)
Mirror formula:
`1/u + 1/v = 1/f`
Substituting the values in the formula above, we get,
`- 1/40 + 1/v = 1/40`
`1/v = 1/40 + 1/40`
`1/v = (1 + 1)/40`
`1/v = 2/40`
`1/v = 1/20`
⇒ v = 20 cm.
The image is behind the mirror at a distance 20 cm.
APPEARS IN
RELATED QUESTIONS
A simple microscope is used by watch repairers. Give reason.
Explain the following term related to spherical lenses:- principal focus
When a spherical mirror is held towards the sun and its sharp image is formed on a piece of carbon paper for some time, a hole is burnt in the carbon paper.
- What is the nature of spherical mirror?
- Why is a hole burnt in the carbon paper?
- At which point of the spherical mirror the carbon paper is placed?
- What name is given to the distance between spherical mirror and carbon paper?
- What is the advantage of using a carbon paper rather than a white paper?
Draw a ray diagram to show the formation of image by a concave mirror for the object beyond its centre of curvature. State three characteristics of the image.
An object of length 4 cm is placed in front of a concave mirror at distance 30 cm. The focal length of mirror is 15 cm.
- Where will the image form?
- What will be the length of image?
Answer the following question.
Write the modification in the curvature of the eye lens which enables us to see the nearby objects clearly?
Define the following term in relation to concave mirror.
Principal focus
The distance from the center of curvature of the mirror to the pole is called the focal length of the mirror.
