$A$ thermodynamic system is taken through the cycle $PQRSP$ as shown in the $PV$ diagram. The net work done by the system is...... $J$. (Note: $1 \text{ kp} = 10^3 \text{ Pa}$,$1 \text{ cc} = 10^{-6} \text{ m}^3$)

Assertion $(A)$: $-NH_2$ group of aniline is ortho,para directing in electrophilic substitutions.
Reason $(R)$: $-NH_2$ group stabilises the arenium ion formed by the ortho,para attack of the electrophile.
The correct answer is

The number of distinct real values of $\lambda$,for which the vectors $-\lambda^2 \hat{i}+\hat{j}+\hat{k}$,$\hat{i}-\lambda^2 \hat{j}+\hat{k}$ and $\hat{i}+\hat{j}-\lambda^2 \hat{k}$ are coplanar,is

The number of oxygen atoms bonded to one phosphorous atom in $P_4O_6$ is

$A$ particle of mass $4 M$ which is initially at rest explodes into three pieces of masses $M$,$M$ and $2 M$. The equal masses move along $X$ and $Y$-axes with velocities $4 ~ms^{-1}$ and $6 ~ms^{-1}$,respectively. The magnitude of the velocity of the heavier mass is

The vapour pressure of water at $23^{\circ} C$ is $19.8 \ mm$. $0.1 \ mole$ of glucose is dissolved in $178.2 \ g$ of water. What is the vapour pressure (in $mm$) of the resultant solution?