Advertisements
Advertisements
Question
Which of the following lens would you prefer to use while reading small letters found in a dictionary?
Options
A convex lens of focal length 5 cm
A concave lens of focal length 5 cm
A convex lens of focal length 10 cm
A concave lens of focal length 10 cm
Advertisements
Solution
A convex lens of focal length 5 cm
APPEARS IN
RELATED QUESTIONS
A lens forms an upright and diminished image of an object when the object is placed at its focal point. Name the lens and draw a ray diagram to show the image formation.
A lens forms an erect, magnified, and virtual image of an object. Draw a labelled ray diagram to show the image formation.
For the object placed between the optical centre and focus of a convex lens, the image is ______.
A small bulb is placed at the principal focus of a convex lens. When the bulb is switched on, the lens will produce
Explain the rules for obtaining images formed by a convex lens with the help of ray diagram.
An object is placed at a distance 20cm from a convex lens of focal length 10cm. Find the image distance and nature of the image.
Draw ray diagrams showing the image formation by a convex lens when an object is placed
- between optical centre and focus of the lens
- between focus and twice the focal length of the lens
- at twice the focal length of the lens
- at infinity
- at the focus of the lens
A student focussed the image of a candle flame on a white screen using a convex lens. He noted down the position of the candle screen and the lens as under
Position of candle = 12.0 cm
Position of convex lens = 50.0 cm
Position of the screen = 88.0 cm
- What is the focal length of the convex lens?
- Where will the image be formed if he shifts the candle towards the lens at a position of 31.0 cm?
- What will be the nature of the image formed if he further shifts the candle towards the lens?
- Draw a ray diagram to show the formation of the image in case (iii) as said above.
Complete the following table based on image formation by convex lens:
| Position of Object | Position of Image | Nature of Image |
| At infinity | (a) ______ | Real and inverted and highly diminished image |
| Beyond 2F1 | (b) ______ | (c) ______ |
| At 2F1 | (d) ______ | Real, inverted, same size (as object) image |
| Between F1 and 2F1 | Beyond 2F2 | (e) ______ |
| At focus F1 | (f) ______ | Real, inverted and highly enlarged image |
A lens forms an upright and magnified image of an object. Draw a labelled ray diagram to show the image formation.
