What will be the angular width of central maxima in Fraunhoffer diffraction when light of wavelength $6000\AA$ is used and slit width is 12×10^–5 cm 

(1) 2 rad

(2) 3 rad

(3) 1 rad

(4) 8 rad

A beam of light of wavelength 600 nm from a distant source falls on a single slit 1 mm wide and the resulting diffraction pattern is observed on a screen 2 m away. The distance between the first dark fringes on either side of the central bright fringe is 

(1) 1.2 mm

(2) 1.2 cm

(3) 2.4 cm

(4) 2.4 mm

Direction of the first secondary maximum in the Fraunhofer diffraction pattern at a single slit is given by (a is the width of the slit) 

(1) $a\sin \theta =\frac{\lambda }{2}$

(2) $a\cos \theta =\frac{3\lambda }{2}$

(3) $a\sin \theta =\lambda$

(4) $a\sin \theta =\frac{3\lambda }{2}$

A parallel monochromatic beam of light is incident normally on a narrow slit. A diffraction pattern is formed on a screen placed perpendicular to the direction of the incident beam. At the first minimum of the diffraction pattern, the phase difference between the rays coming from the edges of the slit is

(1) $0$

(2) $\frac{\pi }{2}$

(3) $\pi$

(4) 2$\pi$

A parallel beam of monochromatic light of wavelength 5000 Å is incident normally on a single narrow slit of width 0.001 mm. The light is focused by a convex lens on a screen placed on the focal plane. The first minimum will be formed for the angle of diffraction equal to 

(1) 0^o

(2) 15^o

(3) 30^o

(4) 60^o

In the far field diffraction pattern of a single slit under polychromatic illumination, the first minimum with the wavelength ${\lambda }_1$ is found to be coincident with the third maximum at ${\lambda }_2$. So

(1) $3{\lambda }_1=0.3{\lambda }_2$

(2) $3{\lambda }_1={\lambda }_2$

(3) ${\lambda }_1=3.5{\lambda }_2$

(4) $0.3{\lambda }_1=3{\lambda }_2$

A beam of light AO is incident on a glass slab (μ = 1.54) in a direction as shown in the figure. The reflected ray OB is passed through a Nicol prism. On viewing through a Nicole prism, we find on rotating the prism that:

Unpolarized light is traveling along Z-axis through three polarizing sheets. The polarizing directions of the first and third sheets are parallel to X-axis and Y-axis respectively whereas that of the second one is at ${60}^0$ to the Y-axis. Then, the fraction of the initial light intensity that emerges from the system is about

1.  Zero 

2.  0.094

3.  0.031

4.  0.28

Unpolarized light falls on two polarizing sheets placed one on top of the other. What must be the angle between the characteristic directions of the sheets if the intensity of the final transmitted light is one-third the maximum intensity of the first transmitted beam?

$Given:$
$\cos {75}^0 =0.26$
$\cos {57}^0 =0.57$
$\cos {35}^0 =0.82$
$\cos {15}^0 =0.96$
$$

(1) 75°

(2) 55°

(3) 35°

(4) 15°

Unpolarized light of intensity 32 Wm^–2 passes through three polarizers such that the transmission axes of the first and second polarizer make an angle of 30° with each other and the transmission axis of the last polarizer is crossed with that of the first. The intensity of the final emerging light will be:

1. 32 Wm^–2

2. 3 Wm^–2

3. 8 Wm^–2

4. 4 Wm^–2