Which of the following statements is $NOT$ correct for potash alum?

An ideal gas follows a process $PT = \text{constant}$. The correct graph between pressure $(P)$ and volume $(V)$ is:

$A$ spherical iron ball of $10 \; cm$ radius is coated with a layer of ice of uniform thickness that melts at a rate of $50 \; cm^{3}/min$. When the thickness of ice is $5 \; cm$,the rate (in $cm/min$) at which the thickness of ice decreases is:

An electron beam travels with a velocity of $1.6 \times 10^7 \ m/s$ perpendicularly to a magnetic field of intensity $0.1 \ T$. Calculate the radius of the path of the electron beam. (Given: $m_e = 9 \times 10^{-31} \ kg$,$e = 1.6 \times 10^{-19} \ C$)

An achromatic combination of lenses produces

The structure of the compound formed when nitrobenzene is reduced by lithium aluminium hydride $(LiAlH_4)$ is