In $YDSE$, the distance of the slits from the screen is increased by $25 \%$ and the separation between the slits is halved. If $W$ represents the original fringe width, the new fringe width is (in $\,W$)

In Young's double-slit experiment, the fringe width will increase if ......

In which of the following is the interference due to the division of wave front?

In a double-slit experiment,the angular width of the fringes is $0.20^o$ for sodium light $(\lambda = 5890 \ \mathring{A})$. In order to increase the angular width of the fringes by $10\%$,the necessary change in the wavelength is:

$A$ beam of light consisting of two wavelengths $7000 \; \mathring{A}$ and $5500 \; \mathring{A}$ is used to obtain an interference pattern in Young's double-slit experiment. The distance between the slits is $2.5 \; mm$ and the distance between the plane of the slits and the screen is $150 \; cm$. The least distance from the central fringe,where the bright fringes due to both the wavelengths coincide,is $n \times 10^{-5} \; m$. The value of $n$ is .............

In a Young's double slit experiment,the wavelength of red light is $7.8 \times 10^{-5} \,cm$ and that of blue light is $5.2 \times 10^{-5} \,cm$. The value of $n$ for which $(n+1)^{\text{th}}$ blue bright band coincides with $n^{\text{th}}$ bright red band is ..........