A. Convex lens
B. Concave lens
C. Concave-convex
D. None of the Above
Check Also
The filament of an electric bulb is made of :
A Carbon B Iron C Tungsten D None of these
A. Convex lens
B. Concave lens
C. Concave-convex
D. None of the Above
A Carbon B Iron C Tungsten D None of these