 Find the focal length of a lens of power negative 2 Diopter so now we know that power is 1 upon the focal length So negative 2 diopter which is meter inverse is 1 upon the focal length in meter So the focal length in meters is negative 1 by 2 that is 50 centimeter here the negative sync device that this is the K-V type of lens and hence our answer is given that the focal length is 50 centimeter What type of lens it is? It is a concave lens. Thank you