Sphenopsida class belongs to

A unit positive point charge is taken slowly through an infinitesimally thin tube that is inside a charged dielectric sphere of radius R, having uniform positive charge density $\rho$, as shown in the figure. The initial and final positions of the charge are marked by A and B at distance 2R and 3R respectively, from the centre of the sphere. In this process, the magnitude of the total work done on the point charge is $\frac{\rho R^{2}}{n\epsilon_{0}}$. The value of n is: ($\epsilon_{0}$ is the permittivity of vacuum) [Image Placeholder]

Consider three media P, Q and R with refractive indices 1, 1.25, and 1.5 respectively. The medium Q having a thickness of 5 cm is placed between extended media P and R as shown in the figure. An object O is placed at the centre of medium Q. If viewed from medium P near the normal direction, the apparent depth of O is $h_1$. For similar observation from medium R, the apparent depth is $h_2$. The value of $|h_{1}-h_{2}|$, in cm, is: [Image Placeholder]

Two moles of an ideal gas undergo free expansion from 10 L to 100 L at 300 K. The values of $\Delta S_{system}$ and $\Delta S_{surroundings}$ are (R is universal gas constant)

Arrange the following taxonomic categories in ascending order. (a) Genus (b) Class (c) Order (d) Phylum (e) Family (f) Kingdom (g) Species. Choose the correct answer from the options given below: