Which of the following pairs of orbitals possess two nodal planes?

$A$ homogeneous solid cylinder of length $L$ $(L < H/2)$ and cross-sectional area $A'$ is immersed such that it floats with its axis vertical at the liquid-liquid interface with length $L/4$ in the denser liquid (density $2d$) and $3L/4$ in the lighter liquid (density $d$) as shown in the figure. The density $D$ of the solid is given by:

$A$ thermodynamic system is taken through the cycle $PQRS P$ process as shown in the figure. The net work done by the system is ......... $J$.

Let $S=\{x \in(-\pi, \pi): x \neq 0, \pm \frac{\pi}{2}\}$. The sum of all distinct solutions of the equation $\sqrt{3} \sec x+\operatorname{cosec} x+2(\tan x-\cot x)=0$ in the set $S$ is equal to

Which one of the following conditions is incorrect for a well-behaved wave function $(\psi)$?

Importance of day length in flowering of plants was first shown in