Hydrated $AlCl_3$ is used as:

$A$ light string passing over a smooth light pulley connects two blocks of masses $m_1$ and $m_2$ (vertically). If the acceleration of the system is $g / 8$,then the ratio of the masses $m_1 : m_2$ (assuming $m_1 > m_2$) is:

The direction ratios of the two lines $AB$ and $AC$ are $1, -1, -1$ and $2, -1, 1$. The direction ratios of the normal to the plane $ABC$ are

Which one of the following pesticides is banned now-a-days?

If $f: R \rightarrow R$ and $g: R \rightarrow R$ are defined by $f(x)=2x+3$ and $g(x)=x^2+7$,then the values of $x$ such that $g(f(x))=8$ are

The enthalpy of combustion of benzene from the following data will be
$(i) \ 6C_{(s)} + 3H_{2(g)} \to C_6H_{6(l)}; \Delta H = + 45.9 \ kJ$
$(ii) \ H_{2(g)} + \frac{1}{2}O_{2(g)} \to H_2O_{(l)}; \Delta H = - 285.9 \ kJ$
$(iii) \ C_{(s)} + O_{2(g)} \to CO_{2(g)}; \Delta H = - 393.5 \ kJ$
........$kJ$