For a transistor,the current amplification factor $\alpha$ is $0.8$. The transistor is connected in a common emitter configuration. The change in the collector current when the base current changes by $6 \, mA$ is ..... $mA$.

What is the gametophytic stage of Pteridophytes?

The number of radial nodes of $3s$ and $2p$ orbitals respectively are

If the pressure at half the depth of a lake is equal to $2/3$ of the pressure at the bottom of the lake,then what is the depth of the lake in $m$? (Assume atmospheric pressure $P_0 = 10^5 \ Pa$,density of water $\rho = 10^3 \ kg/m^3$,and $g = 10 \ m/s^2$)

Which of the following statements are correct?
$(i)$. Genus comprises a group of related species.
$(ii)$. Taxon represents a taxonomic group of individual organisms.
$(iii)$. Family comprises a group of related genera.
$(iv)$. Taxonomic category class includes related orders.

$A$ codon has a sequence of $\underline{A}$,and specifies a particular $\underline{B}$ that is to be incorporated into a $\underline{C}$. What are $\underline{A}, \underline{B}, \underline{C}$ ?
$\underline{A} \quad \underline{B} \quad \underline{C}$