In a Young’s double-slit experiment, the slit separation is doubled. To maintain the same fringe spacing on the screen, the screen-to-slit distance D must be changed to, _____.

(a)

2D

(b)

\(\frac{D}{2}\)

(c)

\(\sqrt{2}\)D

(d)

\(\frac{D}{\sqrt2}\)

When light is incident on a soap film of thickness 5 x 10^–5 cm, the wavelength of light reflected maximum in the visible region is 5320 Å. Refractive index of the film will be, _____.

(a)

1.22

(b)

1.33

(c)

1.51

(d)

1.83

First diffraction minimum due to a single slit of width 1.0 x 10^–5 cm is at 30^o. Then wavelength of light used is,_____.

(a)

400 \(\mathring { A } \)

(b)

500 \(\mathring { A } \)

(c)

600 \(\mathring { A } \)

(d)

700 \(\mathring { A } \)

A ray of light strikes a glass plate at an angle 60^o. If the reflected and refracted rays are perpendicular to each other, the refractive index of the glass is, _____.

(a)

\(\sqrt3\)

(b)

\(\frac{3}{2}\)

(c)

\(\sqrt{\frac{3}{2}}\)

(d)

2

Light transmitted by Nicol prism is, _____.

(a)

partially polarised

(b)

unpolarised

(c)

plane polarised

(d)

elliptically polarised