Which of the following liquid mixtures shows a positive deviation from Raoult's law?

The length of the common chord of the circles of radii $15$ and $20$,whose centers are $25$ units of distance apart,is

During which phase of mitosis do the nuclear envelope and nucleolus completely disappear?

Which of the following complexes is an outer orbital complex?

Let $a = \min \{x^2 + 2x + 3, x \in R\}$ and $b = \lim_{x \to 0} \frac{\sin x \cos x}{e^x - e^{-x}}$. Then the value of $\sum_{r=0}^n a^r b^{n-r}$ is

$A$ monoatomic ideal gas initially at temperature $T_1$ is enclosed in a cylinder fitted with a massless,frictionless piston. By releasing the piston suddenly,the gas is allowed to expand adiabatically to a temperature $T_2$. If $L_1$ and $L_2$ are the lengths of the gas columns before and after expansion respectively,then $\frac{T_2}{T_1}$ is