Wave Optics

In a Young's double slit experiment with light of wavelength λ the separation of slits is d and distance of screen is D such that D >> d >> λ. If the Fringe width is β, the distance from point of maximum intensity to the point where intensity falls to half of maximum intensity on either side is :

Unpolarized light of intensity $I_0$ is incident on surface of a block of glass at Brewster's angle. In that case, which one of the following statements is true ?

A light source, which emits two wavelengths $\lambda_1=400$ nm and $\lambda_2=600$ nm, is used in a Young's double slit experiment. If recorded fringe widths for $\lambda_1$ and $\lambda_2$ are $\beta_1$ and $\beta_2$ and number of fringes for them within a distance $y$ on one side of the central maximum are $m_1$ and $m_2$, respectively, then

Two beams, A and B, of plane polarized light with mutually perpendicular planes of polarization are seen through a polaroid. From the position when the beam A has maximum intensity (and beam B has zero intensity), a rotation of polaroid through 30° makes the two beams appear equally bright. If the initial intensities of the two beams are $I_A$ and $I_B$ respectively, then $\dfrac{I_A}{I_B}$ equals :

Using monochromatic light of wavelength $\lambda$, an experimentalist sets up the Young's double slit experiment in three ways as shown.

If she observes that $y=\beta'$, the wavelength of light used is :

Two monochromatic light beams of intensity 16 and 9 units are interfering. The ratio of intensities of bright and dark parts of the resultant pattern is :

Interference pattern is observed at 'P' due to superimposition of two rays coming out from a source 'S' as shown in the figure. The value of '$l$' for which maxima is obtained at 'P' is :

(R is perfect reflecting surface) :

In an experiment of single slit diffraction pattern, first minimum for red light coincides with first maximum of some other wavelength. If wavelength of red light is 6600 Å, then wavelength of first maximum will be :

A ray of light is incident from a denser to a rarer medium. The critical angle for total internal reflection is $\theta_{iC}$ and the Brewster's angle of incidence is $\theta_{iB}$, such that $\sin\theta_{iC}/\sin\theta_{iB}=\eta=1.28$. The relative refractive index of the two media is :

In a Young's double slit experiment, the distance between the two identical slits is 6.1 times larger than the slit width. Then the number of intensity maxima observed within the central maximum of the single slit diffraction pattern is :

In the Young's double slit experiment using a monochromatic light of wavelength $\lambda$, the path difference (in terms of an integer $n$) corresponding to any point having half the peak intensity is

Young's double slit experiment is carried out by using green, red and blue light, one color at a time. The fringe widths recorded are $\beta_G$, $\beta_R$ and $\beta_B$, respectively. Then,

Column I shows four situations of standard Young's double slit arrangement with the screen placed far away from the slits $\mathrm S_1$ and $\mathrm S_2$. In each of these cases $\mathrm{S_1P_0}=\mathrm{S_2P_0}$, $\mathrm{S_1P_1}-\mathrm{S_2P_1}=\lambda/4$ and $\mathrm{S_1P_2}-\mathrm{S_2P_2}=\lambda/3$, where $\lambda$ is the wavelength of the light used. In the cases B, C and D, a transparent sheet of refractive index $\mu$ and thickness $t$ is pasted on slit $\mathrm S_2$. The thicknesses of the sheets are different in different cases. The phase difference between the light waves reaching a point P on the screen from the two slits is denoted by $\delta(\mathrm P)$ and the intensity by $I(\mathrm P)$. Match each situation given in Column I with the statement(s) in Column II valid for that situation.

In a Young's double slit experiment, the separation between the two slits is $d$ and the wavelength of the light is $\lambda$. The intensity of light falling on slit 1 is four times the intensity of light falling on slit 2. Choose the correct choice(s).

Light travels as a

The phases of the light wave at $c$, $d$, $e$ and $f$ are $\phi_c$, $\phi_d$, $\phi_e$ and $\phi_f$ respectively. It is given that $\phi_c\ne\phi_f$.

Speed of light is