If light source is at focus of concave lens, then after refraction the ray of light will ____________.
parallel to principal axis
will converge at the centre of curvature.
will never be parallel to principal axis
A ray of light after refraction through a lens emerges parallel to the principal axis of the lens. The incident ray passes through :
(a) its optical centre
(b) its first focus
(c) its second focus
(d) the centre of curvature of the first surface.