Which of the following is a long-day plant?

The area (in sq units) of the region bounded by $x=-1, x=2, y=x^2+1$ and $y=2x-2$ is

An engine has an efficiency of $1/6$. When the temperature of the sink is reduced by $62^{\circ}C$,its efficiency is doubled. The temperature of the source is $.........^{\circ}C$.

The increasing order of magnetic moments of the following complexes is:-
$I. [Fe(CN)_6]^{4-}$
$II. [Fe(CN)_6]^{3-}$
$III. [Cr(NH_3)_6]^{3+}$
$IV. [Ni(H_2O)_4]^{2+}$

Dry air is passed through a solution containing $10 \ g$ of solute and $90 \ g$ of water,and then it is passed through pure water. The loss in weight of the solution is $2.5 \ g$ and the loss in weight of the pure solvent is $0.05 \ g$. Calculate the molecular weight of the solute.

If $arg(z) < 0$,then $arg(-z) - arg(z)$ is equal to