REFLECTION OF light
1. From which surface of a mirror-the polished surface or the silvered surface – does most of the light reflect ?
2. In which kinds of mirrors-plane , concave or convex-can you get a virtual image of an object placed in front of it ?
3. What is the principal axis of a spherical mirror ?
4. A concave mirror forms a real image of the same size as that of the object. Where is the object placed ?
5. Can a convex mirror form a real image of an object ?
6. A ray ACB is incident on a spherical mirror whose centre of curvature is C. In which direction will it reflect ?
7. What is the sign of the object-distance when an object is placed before a concave mirror?
8. Where can the position of an object be if a concave mirror forms its erect and virtual image ?
9. A mirror has focal length cm. Is it convex or concave ?
10. What are the values of the angle of incidence and the angle of reflection for normal incidence on a plane mirror ?
11. In the diagram, the ray is incident parallel to the principal axis. Redraw the diagram, showing the reflected ray.
Short-Answer Questions
1. What is silvering of a mirror ?
The Dissertation on Mirrors and Its Types
... size as the original object (see mirror image). In a concave mirror, parallel beams of light becomes a convergent beam, whose rays intersect in the focus ... it violates the second law of thermodynamics: if one placed a cold object on the transmitting side and a hot one on ... elements of radio telescopes. [edit] Face-to-face mirrors Two or more mirrors placed exactly face to face give the appearance of an ...
2. Write the two laws of reflection of light .
3. What do you understand by the radius of curvature of a spherical mirror ?
4. What is the difference between a real image and a virtual image ?
5. Draw a diagram showing the pole, focus, centre of curvature and principal axis of a concave mirror.
6. Convex mirrors are used as rear-view mirrors in scooters, motorcycles , etc. Explain why.
7. Draw ray diagrams to show the formation of images when an object is placed (a) between the pole and focus, and (b) between the centre of curvature and focus.
Long-Answer Questions
1. Describe a method to measure the focal length of a concave mirror.
2. Write the sign convention used for spherical mirrors.
3. By drawing a neat ray diagram, show the formation of the image of a point object placed above the principal axis of a convex mirror. Explain the construction.
Numerical Problems
1. An object is placed at a distance of 12 cm from a concave mirror or radius of curvature 16 cm. Find the position of the image.
2. An object of height 2 cm is placed at a distance of 15 cm from a concave mirror of focal length 10 cm. Draw a scale diagram to locate the image. From the diagram, find the length of the image formed.
3. The image of an object placed 16 cm from a concave mirror is formed at a distance of 24 cm from the mirror. Calculate the possible focal length of the concave mirror from this information.
4. An object is placed 20cm from a convex mirror. Its image is formed 12 cm from the mirror. Find the focal length of the mirror.
5. Find the position, size and nature of the image formed by a spherical mirror from the following data.
6. An object is placed at a distance of 12 cm from a concave mirror. The image formed is real and four times larger than the object. Calculate the distance of the image from the mirror.
7. An object is placed 24 cm from a concave mirror. Its image is inverted and double the size of the object. Find the focal length of the mirror and the position where the image is formed.
The Essay on Mirror Image Analysis
The story Mirror Image, written by Lena Coakley brings up the argument about, who we are and finding ourselves. Are we judged by who we are externally or what our thoughts are internally? Lena Coakley truly captures the idea that who we are as a person is defined by what our values and beliefs are and not what we look like on the outside. The first I time I read this story I found myself very ...
8. Where should an object be placed before a concave mirror of focal length 20 cm so that a real image is formed at a distance of 60 cm from it ?
9. An object is placed at a distance of 12 cm from a convex mirror of radius of curvature 12 cm. Find the position of the image.
10. If the height of the object in the previous problem is 1.2 cm, what will be the height of the image ?
11. When a concave mirror is placed facing the sun, the sun’s rays converge to a point 10 cm from the mirror. Now, an erect, 2-cm-long pin is placed 15 cm away on the principal axis of the mirror. If you want to get the image of the pin on a card, where would you place the card ? What would be the nature and height of the image ?
