The power of a lens of focal length 10 cm is

The power of a lens is defined as the reciprocal of its focal length when expressed in metres. The SI unit for the power of a lens is the dioptre (D), where one dioptre is the power of a lens with a focal length of one metre. To calculate the power for a lens with a focal length of 10 cm, the value must first be converted to metres: 10 cm = 0.1 m. Using the formula P = 1/f (where f is in metres), the calculation becomes P = 1 / 0.1, which equals 10 dioptres. Therefore, a lens with a focal length of 10 cm has a power of 10 dioptres. This relationship demonstrates that shorter focal lengths result in higher optical power, as the lens bends light rays more effectively.