Advertisements
Advertisements
प्रश्न
Light travels in the same straight line path while passing through different media.
विकल्प
True
False
उत्तर १
False.
उत्तर २
False.
APPEARS IN
संबंधित प्रश्न
Analyse the following observation table showing variation of image distance (v) with object distance (u) in case of a convex lens and answer the questions that follow, without doing any calculations:
| S. No. | Object distance u(cm) | Image distance v(cm) |
| 1 | −90 | +18 |
| 2 | −60 | +20 |
| 3 | −30 | +30 |
| 4 | −20 | +60 |
| 5 | −18 | +90 |
| 6 | −10 | +100 |
(a) What is the focal length of the convex lens? Give reason in support of your answer.
(b) Write the serial number of that observation which is not correct. How did you arrive at this conclusion?
(c) Take an appropriate scale to draw ray diagram for the observation at S. No. 4 and find the approximate value of magnification.
Find the nature and focal length of a spherical mirror whose radius of curvature is +24 cm.
In a convex spherical mirror, reflection of light takes place at:
(a) a flat surface
(b) a bent-in surface
(c) a bulging-our surface
(d) an uneven surface
An object is placed at a long distance in front of a convex mirror of radius of curvature 30 cm. State the position of its image.
A man standing in front of a special mirror finds his image having a very small head, a fat body and legs of normal size. What is the shape of:
(a) top part of the mirror?
(b) middle part of the mirror?
(c) bottom part of the mirror?
Give reasons for your choice.
An object is kept at a distance of 5 cm in front of a convex mirror of focal length 10 cm. Calculate the position and magnification of the image and state its nature.
Draw ray diagrams to represent the nature, position and relative size of the image formed by a convex lens for the object placed:
between F1 and the optical centre O of the lens.
Which of the above two cases shows the use of convex lens as a magnifying glass? Give reasons for your choice.
Explain why, a real image can be projected on a screen but a virtual image cannot.
An object is placed at the following distance from a convex lens of focal length 15 cm:
(a) 35 cm
(b) 30 cm
(c) 20 cm
(d) 10 cm
Which position of the object will produce:
(i) a magnified real image?
(ii) a magnified virtual image?
(iii) a diminished real image?
(iv) an image of same size as the object?
Higher-Order Thinking Skills:
A convex mirror is in water. What should be the change in its focal length?
