Advertisements
Advertisements
Question
For an object placed at a distance 20 cm in front of a convex lens, the image is at a distance 20 cm behind the lens. The focal length of the convex lens is ______.
Options
20 cm
10 cm
15 cm
40 cm
Advertisements
Solution
For an object placed at a distance 20 cm in front of a convex lens, the image is at a distance 20 cm behind the lens. The focal length of the convex lens is 10 cm.
APPEARS IN
RELATED QUESTIONS
Explain optical centre of a lens with the help of proper diagram(s).
The diagram below shows a lens as a combination of a glass slab and two prisms.
- Name the lens formed by the combination.
- What is the line XX’ called?
- Complete the path of the incident ray AB after passing through the lens.
- The final emergent ray either meets XX’ at a point or appears to come from a point on XX’. Label it as F. What is this point called?
A ray of light after refraction through a lens emerges parallel to the principal axis of the lens. The incident ray either passes through ______.
Study the diagram shown in Fig. 5.56
what are the two other characteristics of the image?
The diagram given below shows the position of an object OA in relation to a converging lens L whose foci are at F1 and F2.
- Draw two rays to locate the position of the image.
- State the position of the image with reference to the lens.
- Describe three characteristics of the image.
- Describe how the distance of the image from the lens and its size change as the object is moved towards F1.
The diagram given below shows the position of an object OA in relation to a converging lens whose foci are at F1 and F2.
Describe three characteristic of the image.
Make the rrect choices in the following items :
An object is placed 50 cm from a connverging lens of focal length 30 cm. The image produced would be
Make the correct choices in the following items:
lf the image can be focused on a screen it must be
