.67 metre or 67 cms
Power is inversely related to the focal length. So convex lens of focal length 20 cm has less power compared to that having focal length 10 cm
Convert the focal length to meters, then take the reciprocal. That is how the "power" of a lens is calculated.
The focal length of a lens is the distance from the principal foci to the center of the lens.
1.0 diopters
because manifying power has inerse relation with that of focal length
The power of a lens is 1/focal length (measured in meters).
The power of a lens is 1/focal length (measured in meters).
Power is inversely related to the focal length. So convex lens of focal length 20 cm has less power compared to that having focal length 10 cm
A lens of short focal length has a greater power (than a lens of large focal length)
Convert the focal length to meters, then take the reciprocal. That is how the "power" of a lens is calculated.
Focus or focal length?
The size (diameter) of a lens does not determine its focal length. The amount of curvature of the lens does. Citing a diameter for a lens doesn't help us find the focal length. Lenses are ground to specifications that allow short or long focal length. The more curved the lens, the shorter the focal length. You can see this if we specify a given curvature and then start to "flatten" the lens. The focal length will get longer and longer as the lens is flattened. When the lens is flat (has to curvature) the lense has an infinite focal length, just like a piece of flat glass.
i think it is -0.06m i.e. 6cm
to find the new focal length when the lens is put into water it becomes the 4 times the focal length in air.
The focal length of a lens is the distance from the principal foci to the center of the lens.
1.0 diopters
The focal length of a lens is the distance from the center of the lens to the point at which it focuses light rays. The bigger the focal length, the more powerful the lens. ChaCha!