In Young's double slit experiment,the angular width of fringes is $0.20^o$ for sodium light of wavelength $5890 \ \mathring A$. If the complete system is dipped in water,then the angular width of the fringes becomes....$^o$

In Young's experiment,the separation between the $5^{\text{th}}$ maxima and the $3^{\text{rd}}$ minima is how many times the fringe width?

Interference was observed in an interference chamber when air was present. Now,the chamber is evacuated and if the same light is used,a careful observer will see:

In Young's double slit experiment,the two slits act as coherent sources of equal amplitude $A$ and wavelength $\lambda$. In another experiment with the same setup,the two slits are of equal amplitude $A$ and wavelength $\lambda$ but are incoherent. The ratio of the intensity of light at the mid-point of the screen in the first case to that in the second case is

In $Y.D.S.E.$ using red and blue lights of wavelengths $7800 \, \mathring{A}$ and $5200 \, \mathring{A}$,the $n^{th}$ red fringe coincides with the $(n + 1)^{th}$ blue fringe. The value of $n$ is:

In Young's double-slit experiment,when light of wavelength $\lambda_1 = 5898 \ \mathring{A}$ is used,$92$ fringes are observed in a certain region. If light of wavelength $\lambda_2 = 5461 \ \mathring{A}$ is used instead,how many fringes will be observed in the same region?