MEDIUM
10th CBSE
IMPORTANT
Earn 100

A convex lens of focal length 18 cm and a concave lens of focal length 24 cm are placed in contact such that they have a common principal axis. Find the power of their combination. Will the combination behave as a converging or diverging lens?

Important Questions on Reflection and Refraction

MEDIUM
10th CBSE
IMPORTANT
Modern's ABC+ Of Science Physics>Chapter 4 - Reflection and Refraction>Practice Exercise 4D>Q 8
To find the image distance for varying object distances in case of a convex lens, a student obtains on a screen a sharp image of a bright object placed very far from the lens. After that, he gradually moves the object towards the lens and each time focuses its image on the screen.
In which direction - towards or away from the lens, does he move the screen to focus the object?
MEDIUM
10th CBSE
IMPORTANT
Modern's ABC+ Of Science Physics>Chapter 4 - Reflection and Refraction>Practice Exercise 4D>Q 8
To find the image distance for varying object distances in case of a convex lens, a student obtains on a screen a sharp image of a bright object placed very far from the lens. After that, he gradually moves the object towards the lens and each time focuses its image on the screen.
What happens to the size of image - does it increase or decrease?
MEDIUM
10th CBSE
IMPORTANT
Modern's ABC+ Of Science Physics>Chapter 4 - Reflection and Refraction>Practice Exercise 4D>Q 8
To find the image distance for varying object distances in case of a convex lens, a student obtains on a screen a sharp image of a bright object placed very far from the lens. After that, he gradually moves the object towards the lens and each time focuses its image on the screen.
What happens when he moves the object very close to the lens?
MEDIUM
10th CBSE
IMPORTANT
Modern's ABC+ Of Science Physics>Chapter 4 - Reflection and Refraction>Practice Exercise 4D>Q 9
"A convex lens can form a magnified, erect as well as inverted image of an object placed in front of it”. Draw ray diagram to justify this statement stating the position of the object with respect to the lens in each case.
MEDIUM
10th CBSE
IMPORTANT
Modern's ABC+ Of Science Physics>Chapter 4 - Reflection and Refraction>Practice Exercise 4D>Q 9
An object of height 4 cm is placed at a distance of 20 cm from a concave lens of focal length 10 cm. Use lens formula to determine the position of the image formed.
MEDIUM
10th CBSE
IMPORTANT
Modern's ABC+ Of Science Physics>Chapter 4 - Reflection and Refraction>Practice Exercise 4D>Q 10
What is meant by power of a lens? What does its sign (+ ve or -ve) indicate? State its SI unit. How is it related to the focal length of a lens?
MEDIUM
10th CBSE
IMPORTANT
Modern's ABC+ Of Science Physics>Chapter 4 - Reflection and Refraction>Practice Exercise 4D>Q 11
Draw ray diagrams to show the formation of three times magnified (a) real and (b) virtual image of an object by a converging lens. Mark the positions of O, F and 2F in each diagram.
EASY
10th CBSE
IMPORTANT
Modern's ABC+ Of Science Physics>Chapter 4 - Reflection and Refraction>PRACTICE QUESTIONS>Q 1
The image of a distant object is obtained on a screen by using a concave mirror. The focal length of the mirror is measured by the distance between