A luminous object is placed at a distance of 30cm from the convex lens of focal length 20cm. On the other side of the lens, at what distance from the lens, a convex mirror of radius of curvature 10cm must be placed to have an upright image of the object coinciding with it:
Correct answer: C. 50cm
- A. 12cm
- B. 30cm
- C. 50cm
- D. 60cm
Explanation
For the image of the object to coincide with it, the image formed by the convex lens must be located at the center of curvature of the convex mirror. Using the lens formula, the image distance from the lens is calculated. Then, using the mirror formula, the required distance of the mirror is determined to be 50cm, as the correct answer. Option A and B are incorrect as they do not consider the proper alignment of the lens and mirror. Option D is also incorrect as it does not follow the correct optical principles for this scenario.
Last updated
About Optics
Light is studied through reflection, refraction, dispersion, interference, diffraction and polarization, linking ray behavior with its wave nature. Questions may involve mirrors, lenses, optical instruments, refractive index and image formation, while geometrical optics deals with rays and wave optics explains effects such as interference and diffraction.
Practise Optics
665 free Optics MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Physics questions like this
Physics is on 7 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
8If the two sound waves produce beats, it is necessary that the two have:
A 16 cm long image of an object is formed by a convex lens on a screen placed normal to its principal axis. On moving the lens towards the screen, without changing the positions of the object and the screen, a 9 cm long image is formed again on the screen. The size of the object is:
A 4 cm high object is located 10 cm from the converging lens, whose focal length is 20 cm. The image so formed will be
A beam of electrons can
A beam of electrons can: