The speed of light in an isotropic medium depends on, ______.

(a)

its intensity

(b)

its wavelength

(c)

the nature of propagation

(d)

the motion of the source w.r.t medium

A rod of length 10 cm lies along the principal axis of a concave mirror of focal length 10 cm in such a way that its end closer to the pole is 20 cm away from the mirror. The length of the image is, ______.

(a)

2.5 cm

(b)

5cm

(c)

10 cm

(d)

15cm

An object is placed in front of a convex mirror of focal length off and the maximum and minimum distance of an object from the mirror such that the image formed is real and magnified.

(a)

2f and c

(b)

c and \(\infty\)

(c)

f and O

(d)

None of these

For light incident from air on a slab of refractive index 2, the maximum possible angle of refraction is, ______.

(a)

30^o

(b)

45^o

(c)

60^o

(d)

90^o

If the velocity and wavelength of light in air is V_a and λ_a and that in water is V_w and λ_w, then the refractive index of water is______.

(a)

\(\frac{V_W}{V_a}\)

(b)

\(\frac{V_a}{V_W}\)

(c)

\(\frac{\lambda_W}{\lambda_a}\)

(d)

\(\frac{{V_a}\lambda_a}{{V_W}\lambda_W}\)

Stars twinkle due to, ______.

(a)

reflection

(b)

total internal reflection

(c)

refraction

(d)

polarisation

When a biconvex lens of glass having refractive index 1.47 is dipped in a liquid, it acts as plane sheet of glass. This implies that the liquid must have refractive index, ______.

(a)

less than one

(b)

less than that of glass

(c)

greater than that of glass

(d)

equal to that of glass

The radius of curvature of curved surface at a thin planoconvex lens is 10 cm and the refractive index is 1.5. If the plane surface is silvered, then the focal length will be, ______.

(a)

5 cm

(b)

10 cm

(c)

15 cm

(d)

20 cm

An air bubble in glass slab of refractive index 1.5 (near normal incidence) is 5 cm deep when viewed from one surface and 3 cm deep when viewed from the opposite face. The thickness of the slab is ______.

(a)

8 cm

(b)

10 cm

(c)

12 cm

(d)

16 cm

A ray of light travelling in a transparent medium of refractive index n falls, on a surface separating the medium from air at an angle of incidents of 45^o . The ray can undergo total internal reflection for the following n, ______.

(a)

n = 1.25

(b)

n = 1.33

(c)

n = 1.4

(d)

n = 1.5