The focal length of a convex lens is 20 cm, the focal length of the concave mirror is 30 cm. And the separation between lens and mirror is 90 cm. If the object is placed 60 cm before the lens, find out the position of an image formed by the concave mirror?
60 cm from point B
60 cm from point A
60 cm left of lens
90 cm from point B
Compare two quantities — Quantity A and Quantity B — and then determine which of the following statements describes the comparison:
In a lens, if
u - distance of the object from the lens
v - distance of the image from the lens
hi - height of the image
h - height of the object
- Quantity B is greater.
- Quantity A is greater
- The two quantities are equal.
- The relationship cannot be determined from the information given.
OA is an object with image size 4 cm and O'A' is the image of the object. Find the image height and nature of the image formed.
3 cm, erect
4 cm, inverted
A 10 cm tall candle, when viewed using a convex lens, appears to be 20 cm tall. The focal length of the lens is 5 cm. What is the object distance?
Which of the following is true about lenses?
convex mirror has positive focal length and concave lens have positive focal length
both convex mirror and convex lens have negative focal length.
convex mirror has positive focal length and concave lens have negative focal length
convex mirror has negative focal lengths concave lens have positive focal length
What is the nature of the lens and the position of the object if the image formed is of the same size as that of the object?
concave lens, at 2F1
convex lens, at F1
convex lens, at 2F1
concave lens, at F1
An object is placed at 30 cm in front of the convex lens of focal length 10 cm. Find out the image distance from the lens?
+ 15 cm