In the propagation of electromagnetic waves, the angle between the direction of propagation and plane of polarisation is:

(1) 0^o

(2) 45^o

(3) 90^o

(4) 180^o

An unpolarised light incident on a polariser has amplitude A, and the angle between analyzer and polariser is \(60^{\circ}\). The light transmitted by the analyzer has an amplitude of:

1. $A\sqrt{2}$

2. $A/2\sqrt{2}$

3. $\sqrt{3}A/2$

4. A/2

Light passes successively through two polarimeters tubes each of length 0.29m. The first tube contains dextro rotatory solution of concentration 60kgm^–3 and specific rotation 0.01rad m²kg^–1. The second tube contains laevo rotatory solution of concentration 30kg/m³ and specific rotation 0.02 radm²kg^–1. The net rotation produced is 

(1) 15°

(2) 0°

(3) 20°

(4) 10°

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

(1) 32 Wm^–2

(2) 3 Wm^–2

(3) 8 Wm^–2

(4) 4 Wm^–2

In the visible region of the spectrum the rotation of the place of polarization is given by $\theta =a+\frac{b}{{\lambda }^2}$. The optical rotation produced by a particular material is found to be 30° per mm at $\lambda =5000$Å and 50° per mm at $\lambda =4000\text{Å}$. The value of constant a will be

(1) $+\frac{50°}{9}$per mm

(2) $-\frac{50°}{9}$per mm

(3) $+\frac{9°}{50}$per mm

(4) $-\frac{9°}{50}$per mm

When an unpolarized light of intensity I₀ is incident on a polarizing sheet, the intensity of the light which does not get transmitted is 

(1) Zero

(2) I₀

(3) $\frac{1}{2}{I}_0$

(3) $\frac{1}{4}{I}_0$

Two polaroids are placed in the path of unpolarized beam of intensity I₀ such that no light is emitted from the second polaroid. If a third polaroid whose polarization axis makes an angle θ with the polarization axis of first polaroid, is placed between these polaroids then the intensity of light emerging from the last polaroid will be:

(1) $\left(\frac{{\displaystyle I_0}}{{\displaystyle 8}}\right){\sin }^{2}2\theta$

(2) $\left(\frac{{\displaystyle I_0}}{{\displaystyle 4}}\right){\sin }^{2}2\theta$

(3) $\left(\frac{{\displaystyle I_0}}{{\displaystyle 2}}\right){\cos }^4\theta$

(4) $I_0{\cos }^4\theta$

In the adjacent diagram, CP represents a wavefront and AO & BP, the corresponding two rays. What would be the condition on θ for constructive interference at P between the ray BP and reflected ray OP?

(1) cosθ = 3λ/2d

(2) cosθ = λ/4d$\theta$

(3) secθ – cosθ = λ/d

(4) secθ – cosθ = 4λ/d

In the Young's double slit experiment, if the phase difference between the two waves interfering at a point is ϕ, the intensity at that point can be expressed by the expression-

(where A and B depend upon the amplitudes of the two waves)

(1) $I=\sqrt{A^2+B^2{\cos }^2\varphi }$

(2) $I=\frac{A}{B}\cos \varphi$

(3) $I=A+B\cos \frac{\varphi }{2}$

(4) $I=A+B\cos \varphi$

When one of the slits of Young’s experiment is covered with a transparent sheet of thickness 4.8 mm, the central fringe shifts to a position originally occupied by the 30^th bright fringe. What should be the thickness of the sheet if the central fringe has to shift to the position occupied by 20^th bright fringe 

(1) 3.8 mm

(2) 1.6 mm

(3) 7.6 mm

(4) 3.2 mm