The wavelength of red light from He-Ne laser is 633 nm in air but 474 nm in the aqueous humor inside the eye ball. Then the speed of red light through the aqueous humor is
3 × 108 m/s
1.34 × 108 m/s
2.25 × 108 m/s
2.5 × 108 m/s
The radius of curvature of the convex face of a planoconvex lens is 15 cm and the refractive index of the material is 1.4.Then the power of the lens in dioptre is
1.6
1.66
2.6
2.66
D.
2.66
Magnification at least distance of distinct vision of a simple microscope having its focal length 5 cm is
2
4
5
6
The position of final image formed by the given lens combination from the third lens will be at a distance of (f1 = +10 cm, f2 = − 10 cm, f3 = + 30 cm)
15 cm
infinity
45 cm
30 cm
If the polarizing angle of a piece of glass for green light is 54.7 4°, then the angle of minimum deviation for an equilateral prism made of same glass is [Given : tan 54.74° = 1.414]
45°
54.74°
30°
90°
The optical fibres have an inner core of refractive index n1 and a cladding of refractive index n2 such that
n1 = n2
n1 ≤ n2
n1 < n2
n1 > n2
A ray of light passes from vacuum into a medium of refractive index, the angle of incidence is found to be twice the angle of refractlon. Then the angle of incidence is
If ε0 and µ0 are the electric permittivity and magnetic permeability of free space and ε and µ are the corresponding quantities in the medium, the index of refraction of the medium in terms of above parameter is
A light ray of 5895 wavelength travelling in vacuum enters a medium of refractive index 1.5. The speed of light m the medium is
3 × 108 m/s
2 × 108 m/s
1.5 × 108 m/s
6 × 108 m/s
The plane faces of two identical plano-convex lenses each having a focal length of 50 cm are placed against each other to form a usual biconvex lens. The distance from this lens combination at which an object must be placed to obtain a real, inverted image which has the same size as the object is
50 cm
25 cm
100 cm
40 cm