The probability of electrons to be found in the conduction band of an intrinsic semiconductor at a finite temperature

In a Young's double slit experiment,$12$ fringes are observed to be formed in a certain segment of the screen,when light of wavelength $600 \, nm$ is used. If the wavelength of light is changed to $400 \, nm$,the number of fringes observed in the same segment of the screen will be

The distribution of relative intensity $I(\lambda)$ of blackbody radiation from a solid object versus the wavelength $\lambda$ is shown in the figure. If the Wien displacement law constant is $2.9 \times 10^{-3} \ mK$,what is the approximate temperature of the object in $K$?

$A$ circle with center at $(2,4)$ is such that the line $x+y+2=0$ cuts a chord of length $6$. The radius of the circle is

What effect does branching of an alkane chain have on its boiling point?

$A$ glass capillary tube of inner diameter $0.28 \ mm$ is lowered vertically into water in a vessel. The pressure to be applied on the water in the capillary tube so that the water level in the tube is the same as that in the vessel (in $N/m^2$) is:
(Surface tension of water $= 0.07 \ N/m$,Atmospheric pressure $= 10^5 \ N/m^2$)