$A$ gaseous mixture consists of $16 \, g$ of helium and $16 \, g$ of oxygen. The ratio $(C_p / C_v)$ of the mixture is

What is meant by 'demineralised' water and how can it be obtained?

$A$ bag $X$ contains $2$ white and $3$ black balls and another bag $Y$ contains $4$ white and $2$ black balls. One bag is selected at random and a ball is drawn from it. Then,the probability for the ball chosen to be white is:

When the margins of sepals or petals overlap one another without any particular direction,the condition is termed as

In the Davisson-Germer experiment, an electron beam of energy $75 \ eV$ falls normally on the surface of a crystal. If the maximum intensity is obtained at an angle of $45^{\circ}$ to the direction of the incident beam, then the inter-atomic distance in the lattice plane of the crystal will be :-............... $\mathring{A}$

If the circle $x^2+y^2+6x-2y+k=0$ bisects the circumference of the circle $x^2+y^2+2x-6y-15=0$,then $k$ is equal to :