Two containers of equal volume contain the same gas at pressure $P_1$ and $P_2$ and absolute temperature $T_1$ and $T_2$ respectively. On joining the vessels,the gas reaches a common pressure $P$ and common temperature $T$. The ratio $P/T$ is equal to

An element $P$ has atomic number $56$. What will be the formula of its halide?

Nitrogen fixation in the root nodules of $Alnus$ is performed by:

$A$ projectile is fired from the surface of the earth with a velocity of $5\, ms^{-1}$ at an angle $\theta$ with the horizontal. Another projectile fired from another planet with a velocity of $3\, ms^{-1}$ at the same angle follows a trajectory which is identical to the trajectory of the projectile fired from the earth. The value of the acceleration due to gravity on the planet is (in $ms^{-2}$) (given $g = 9.8\, ms^{-2}$):

If $A = \begin{bmatrix} 1 & 2 & 2 \\ 2 & 1 & 2 \\ 2 & 2 & 1 \end{bmatrix}$,then $A^3 - 4A^2 - 6A$ is equal to:

$A, B$ and $C$ are three points in a uniform electric field as shown in the figure. The electric potential is