Physics
A convex lens has focal length 12 cm with an object at a distance of 20 cm in front of the lens. He obtains a blurred image on the screen placed at a distance of 23 cm in front of the lens. In order to obtain the clear image, he has to move the screen
- towards the lens.
- away from the lens.
- to a position very far away from the lens.
- either towards or away from the lens.
Related Questions
White light is dispersed by a prism. Inside the prism, compared to the blue light, the red light
- slows down less and refracts more
- slows down more and refracts less
- slows down more and refracts more
- slows down less and refracts less
An endoscope uses optic fiber to transmit high resolution images of internal organs without loss of information. The principle of light that is used by the optic fiber is based on :
- refraction
- reflection
- scattering
- total internal reflection
Assertion (A) : Infrared radiations travel long distance through a dense fog and mist.
Reason (R) : Infrared radiations undergo minimal scattering in earth's atmosphere.
- both A and R are true and R is the correct explanation of A.
- both A and R are True and R is not the correct explanation of А.
- assertion is false but reason is true.
- assertion is true but reason is false.
Two sound waves X and Y have the same amplitude and the same wave pattern but their frequencies are 60 Hz and 120 Hz respectively, then
- X will be shriller and Y will be grave
- X will be grave and Y will be shriller
- X will differ in quality than Y
- X is louder than Y