$C_6H_6 + 3O_3$ $\longrightarrow X \stackrel{Zn / H_2O}{}$ ${\longrightarrow} Y$; $X$ and $Y$ are respectively

The ratio of the specific heat capacities of a gas is $1.5$. When the gas undergoes an adiabatic process, its volume is doubled and pressure becomes $P_1$. When the gas undergoes an isothermal process, its volume is doubled and pressure becomes $P_2$. If $P_1 = P_2$, the ratio of the initial pressures of the gas when it undergoes adiabatic and isothermal processes is

If the amplitude of $z - 2 - 3i$ is $\pi / 4$,then the locus of $z = x + iy$ is

Which of the following cannot be used in Friedel-Crafts reactions?

$A$ straight line is equally inclined to all the three coordinate axes. Then, the angle made by the line with the $y$-axis is

The technique used to make numerous copies of a specific segment of $DNA$ quickly and accurately is