MEDIUM
10th CBSE
IMPORTANT
Earn 100

A convex lens has focal length of 18 cm. At what distance from the lens an object be placed so that it forms a real image three times the size of the object?

Important Questions on Light - Reflection and Refraction

MEDIUM
10th CBSE
IMPORTANT
Science Part-I NEW ERA PHYSICS Textbook for Class X>Chapter 4 - Light - Reflection and Refraction>PROBLEMS FOR PRACTICE>Q 5
An object 50 cm tall is placed on the principal axis of a convex lens. Its 20 cm tall image is formed on the screen placed at a distance of 10 cm from the lens. Calculate the focal length of the lens.
MEDIUM
10th CBSE
IMPORTANT
Science Part-I NEW ERA PHYSICS Textbook for Class X>Chapter 4 - Light - Reflection and Refraction>PROBLEMS FOR PRACTICE>Q 6
A concave lens has focal length of 10 cm. At what distance from the lens a 5 cm tall object be placed so that it forms an image at 6 cm from the lens? Also calculate the size of the image formed.
MEDIUM
10th CBSE
IMPORTANT
Science Part-I NEW ERA PHYSICS Textbook for Class X>Chapter 4 - Light - Reflection and Refraction>PROBLEMS FOR PRACTICE>Q 7
A convex lens has a focal length of 40 cm. Calculate its power.
MEDIUM
10th CBSE
IMPORTANT
Science Part-I NEW ERA PHYSICS Textbook for Class X>Chapter 4 - Light - Reflection and Refraction>PROBLEMS FOR PRACTICE>Q 8
A thin lens has a focal length of -25 cm. What is the power of the lens? Is it convex or concave?
MEDIUM
10th CBSE
IMPORTANT
Science Part-I NEW ERA PHYSICS Textbook for Class X>Chapter 4 - Light - Reflection and Refraction>PROBLEMS FOR PRACTICE>Q 9
A convergent lens of power 8 D is combined with a divergent lens of power -10 D. Calculate focal length of the combination.
MEDIUM
10th CBSE
IMPORTANT
Science Part-I NEW ERA PHYSICS Textbook for Class X>Chapter 4 - Light - Reflection and Refraction>PROBLEMS FOR PRACTICE>Q 10
Convex lens of focal length 20 cm and concave lens of focal length 10 cm are placed in contact. Calculate (i) Total power of combination, (ii) What is the nature of the combination.
EASY
10th CBSE
IMPORTANT
Science Part-I NEW ERA PHYSICS Textbook for Class X>Chapter 4 - Light - Reflection and Refraction>Test Your Self Exercise 2>Q 1
A student obtained a sharp image of the grill of a window on a screen, using a convex lens. For getting better results, the teacher suggested focusing a distant tree instead of the grill. In which direction should the lens be moved for this purpose? 
EASY
10th CBSE
IMPORTANT
Science Part-I NEW ERA PHYSICS Textbook for Class X>Chapter 4 - Light - Reflection and Refraction>Test Your Self Exercise 2>Q 2
Give the diagram which represents the correct angle of incidence i, angle of refraction r and angle of emergence e for the experiment tracing the path of a ray of light passing through a rectangular glass slab.