If the distance between the foci of an ellipse is $6$ and the length of the minor axis is $8$,then the eccentricity is

If the magnetic dipole moment of an atom of diamagnetic material,paramagnetic material and ferromagnetic material are denoted by $\mu_d$,$\mu_p$ and $\mu_f$ respectively,then

At a certain temperature,the equilibrium constant $K_c$ is $0.25$ for the reaction:
$A_{2(g)} + B_{2(g)} \rightleftharpoons C_{2(g)} + D_{2(g)}$
If we take $1 \ mol$ of each of the four gases in a $10 \ L$ container,what would be the equilibrium concentration of $A_{2(g)}$ (in $M$)?

$A$ wind with speed $40\,m/s$ blows parallel to the roof of a house. The area of the roof is $250\,m^2.$ Assuming that the pressure inside the house is atmospheric pressure,the force exerted by the wind on the roof and the direction of the force will be $(\rho_{air} = 1.2\,kg/m^3)$

The $pH$ of $0.05 \ M$ acetic acid is $(K_a = 2 \times 10^{-5})$

$\lim _{x \rightarrow 0} \frac{\sin x \sin ^{-1} x}{x^2}$ is equal to