Arrange the following substrate in decreasing order of electrophilic addition reaction

Two containers of equal volume contain the same gas at pressure $P_1$ and $P_2$ and absolute temperature $T_1$ and $T_2$ respectively. On joining the vessels,the gas reaches a common pressure $P$ and common temperature $T$. The ratio $P/T$ is equal to

Each category of taxonomic hierarchy is referred to as a unit of . . . . . . .

The colour sequence in a carbon resistor is red,brown,orange,and silver. The resistance of the resistor is:

Which one of the following is heterosporous?

The gravitational force acting on a particle,due to a solid sphere of uniform density and radius $R$,at a distance of $3 R$ from the centre of the sphere is $F_1$. $A$ spherical hole of radius $(R / 2)$ is now made in the sphere as shown in the figure. The sphere with hole now exerts a force $F_2$ on the same particle. Ratio of $F_1$ and $F_2$ is