Which one of the following equations represents the variation of viscosity coefficient $(\eta)$ with temperature $(T)$?

$A$ ball $A$ of mass $m$ moving along the positive $x$-direction with kinetic energy $K$ and momentum $p$ undergoes an elastic head-on collision with a stationary ball $B$ of mass $M$. After the collision,ball $A$ moves along the negative $x$-direction with kinetic energy $K/9$. The final momentum of ball $B$ is:

In the final answer of the expression $\frac{(29.2-20.2)(1.79 \times 10^5)}{1.37}$,the number of significant figures is:

In which of the following molecules is the $N$ atom not $sp^2$ hybridized?

The incorrect stability order of $+3$ and $+1$ states of $13^{th}$ group elements (boron family) is

$A$ radioactive material decays by simultaneous emission of two particles with respective half-lives $1620 \ years$ and $810 \ years$. The time (in years) after which one-fourth of the material remains is