Power of biconvex lens is P diopter. When it is cut into two symmetrical halves by a plane containing the principal axis. The ratio of power of two halves is

Step-by-step solution

Power of equiconvex lens =P i.e P= 1 f , where f is focal length of equiconvex lens. When an equiconvex lens is cut into two symmetrical halves by a plane containing the principal axis, then its focal length remains same. Hence, power of lens (each halves) aligned & P^ = 1 f P^ =P & P^ P =1 & P: P=1: 1 aligned