Physics
If half part of a convex lens is covered, the focal length …………… but the intensity of the image ……………
- increases, decreases
- decreases, increases
- does not change, increases
- does not change, decreases
Refraction Lens
12 Likes
Answer
does not change, decreases
Reason — If part of the lens is covered, its focal length remains unchanged, only the amount of light entering the lens decreases due to which the intensity of image decreases but the position, size and nature of image formed by it do not change.
Answered By
9 Likes
Related Questions
The focal length of a lens depends upon :
- the refractive index of the material of lens relative to its surrounding medium
- the amount of light entering the lens
- the radius of curvature of the two surfaces of lens
- both (1) and (3)
If a lens is placed in water instead of air, its focal length :
- increases
- decreases
- remains the same
- can both increase or decrease
The focal length of a thin convex lens is …………… than that of a thick lens.
- less
- more
- same
- none of the above
The radius of the sphere whose part is the lens surface is called the …………… of that surface.
- centre of curvature
- focal length
- pole
- radius of curvature