How many atoms of calcium will be deposited from a solution of $CaCl_2$ by a current of $25 \ mA$ flowing for $60 \ s$?

The central fringe of the interference pattern produced by light of wavelength $6000 \, \mathring{A}$ is found to shift to the position of the $4^{th}$ bright fringe after a glass plate of refractive index $1.5$ is introduced. The thickness of the glass plate would be ........ $\mu m$.

Which metal is protected by a layer of its own oxide?

The spectrum of a black body at two temperatures $27^oC$ and $327^oC$ is shown in the figure. Let $A_1$ and $A_2$ be the areas under the two curves respectively. The value of $\frac{A_2}{A_1}$ is

If $X$ is a Poisson variate such that $P(X=1)=2 P(X=2)$, then $P(X=3)$ is equal to

The eccentricity of the conic $36x^2 + 144y^2 - 36x - 96y - 119 = 0$ is