Advertisements
Advertisements
प्रश्न
A small bulb is placed at the principal focus of a convex lens. When the bulb is switched on, the lens will produce
विकल्प
a convergent beam of light
a divergent beam of light
a parallel beam of light
a coloured beam of light
उत्तर
A convergent beam of light
APPEARS IN
संबंधित प्रश्न
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 converging lens forms the image of an object placed in front of it, beyond 2F2 of the lens. State three characteristics of the image.
Draw a ray diagram to show how a converging lens can form a real and enlarged image of an object.
A lens forms an inverted image of an object. What is the nature of the image real or virtual?
An object is placed at a distance 2f from a convex lens of focal length f. The size of the image formed is ______ that of the object.
Explain the rules for obtaining images formed by a convex lens with the help of ray diagram.
An object of height 3cm is placed at 10cm from a concave lens of focal length 15cm. Find the size of the image.
Sudha finds out that the sharp image of the window pane of her science laboratory is formed at a distance of 15 cm from the lens. She now tries to focus the building visible to her outside the window instead of the window pane without disturbing the lens. In which direction will she move the screen to obtain a sharp image of the building? What is the approximate focal length of this lens?
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
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 |
