EASY
12th West Bengal Board
IMPORTANT
Earn 100

Light from an object passes through a thin converging lens, of focal length 20 cm placed 24 cm from the object and then through a thin diverging lens of focal length 50cm and the final real image is formed 62.5 cm away from the concave lens. Find the position of the image due to the first lens

Important Questions on Refraction at Spherical Surfaces and Spherical Lens

EASY
12th West Bengal Board
IMPORTANT
A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 14 - Refraction at Spherical Surfaces and Spherical Lens>EXERCISE 14>Q 22
A convex lens formed a real image of an object at a distance 20 cm from it. When a concave lens was placed 5 cm away from the convex lens towards the screen, the image moved 10 cm further away. What was the focal length and power of the concave lens?
EASY
12th West Bengal Board
IMPORTANT
A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 14 - Refraction at Spherical Surfaces and Spherical Lens>EXERCISE 14>Q 23
If the focal length of a lens is inversely proportional to (μ-1), μ being the refractive index, and has a value 50 mm for violet light, what will be the focal length for red light? μ for violet =1.532 and for red =1.512.
EASY
12th West Bengal Board
IMPORTANT
A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 14 - Refraction at Spherical Surfaces and Spherical Lens>EXERCISE 14>Q 24
The distance between an object and a thin diverging lens is m times greater than the focal length of the lens. How many times smaller will be the image than the object be?
EASY
12th West Bengal Board
IMPORTANT
A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 14 - Refraction at Spherical Surfaces and Spherical Lens>EXERCISE 14>Q 25
An object is placed in front of a convex lens at such a distance away that the lens forms a real image of same size. Then the object is moved 16 cm towards the lens. The image still remains real but is magnified three times. Calculate the focal length of the lens. 
EASY
12th West Bengal Board
IMPORTANT
A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 14 - Refraction at Spherical Surfaces and Spherical Lens>EXERCISE 14>Q 27
The diameter of the sun is 1.4×109 m and the sun is at a distance of 1.5×1011 m from the earth. If a convex lens (f=20 cm) form an image of the sun, what will be the diameter of the image ? 
MEDIUM
12th West Bengal Board
IMPORTANT
A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 14 - Refraction at Spherical Surfaces and Spherical Lens>EXERCISE 14>Q 2
An image 1 cm long of an object is formed on a screen by a convex lens. Keeping the object and screen fixed, the lens is moved until another image is formed on the screen. If this image is 0.75 cm long, what is the length of the object ?
EASY
12th West Bengal Board
IMPORTANT
A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 14 - Refraction at Spherical Surfaces and Spherical Lens>EXERCISE 14>Q 3
An object and its real image are located at distances 25 cm and 40 cm respectively from the two principal foci of a lens. Find the focal length and the linear magnification of the image.
EASY
12th West Bengal Board
IMPORTANT
A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 14 - Refraction at Spherical Surfaces and Spherical Lens>EXERCISE 14>Q 4
An object is at a distance D cm from a screen. A convex lens of focal length f forms an image of the object on the screen. When the lens is shifted through a distance x cm, another sharp image is formed on the screen. Show that x=D(D-4f).