Advertisements
Advertisements
Question
The distance from the pole to the focus is called ______.
Options
pole length
focal length
principal axis
None of the above
Advertisements
Solution
The distance from the pole to the focus is called focal length.
Explanation:
The distance from the pole (the center of a spherical mirror or lens) to the focus (the point where light rays converge or appear to diverge) is called the focal length.
APPEARS IN
RELATED QUESTIONS
Image formed by a convex ______ is always virtual and smaller in size.
Match the items given in Column I with one or more items of Column II.
| Column I | Column II | ||
| (a) | A plane mirror | (i) | Used as a magnifying glass. |
| (b) | A convex mirror | (ii) | Can form image of objects spread over a large area. |
| (c) | A convex lens | (iii) | Used by dentists to see enlarged image of teeth. |
| (d) | A concave mirror | (iv) | The image is always inverted and magnified. |
| (e) | A concave lens | (v) | The image is erect and of the same size as the object. |
| (vi) | The image is erect and smaller in size than the object. |
A ray of light strikes a plane mirror at an angle of 40° to the mirror surface. What will be the angle of reflection?
What type of image is formed:
on a cinema screen?
When a spherical mirror is held towards the sun and its sharp image is formed on a piece of a carbon paper for some time, a hole is burnt in the carbon paper.
At which point of the spherical mirror the carbon paper is placed?
Name the spherical mirror which can produce a real and diminished image of an object.
The shiny outer surface of a hollow sphere of aluminium of radius 50 cm is to be used as a mirror:
State whether this spherical mirror will diverge or converge light rays.
Name the spherical mirror which (i) diverges (ii) converges the beam of light incident on it. Justify your answer by drawing a ray diagram in each case.
Define the following terms in the context of a diverging mirror:
- Principal focus
- Focal length
Draw a labelled ray diagram to illustrate your answer.
