After all possible reflection and refractions the final image is located at a distance 'x' cm from air-glass interface. Then value of 7x is

An image is formed at a distance of 100 cm from the glass surface with refractive index 1.5, when a point object is placed in the air at a distance of 100 cm from the glass surface. The radius of curvature is of the surface is

An image is formed at a distance of 100 cm from the glass surface with refractive index 1.5, when a point object is placed in the air at a distance of 100 cm from the glass surface. The radius of curvature is of the surface is

A ray of light strikes an air-glass interface such that a part of it is reflected into air and the rest enters glass as shown in the figure below. If angle of refraction and refractive index of glass with respect to air is r and mu respectively,then value of alpha is