List of practice Questions

In the metallury of aluminium, purified $Al_2O_3$ is mixed with $Na_3AlF_6$ or $CaF_2$. $Na_3AlF_6$ or $CaF_2$ lowers the melting point of mixture and increases its conductivity.
In the phenomenon of mutual induction, self induction of each of the coil persists Self induction arises when strength of current in one coil changes. In mutual induction, current is changing in both the individual coils
In the presence of alkaline $KMnO_{4} 4-$ methylacetophenone is oxidised to benzoic acid. Keto group is oxidised to $??OOH$ group.
In the reaction, $2Cu_{2}O_{\left(s\right)}+Cu_{2}S_{\left(s\right)} \rightarrow 6 Cu_{\left(s\right)}+SO_{2\left(g\right)}$ copper acts as a reductant and sulphur acts as an oxidant. The given reaction is not a redox reaction.
In some flowers like lily, perianth is a term used when calyx and corolla are not distinct. Calyx and corolla are the reproductive organs.
In some leguminous plants, the leaf base is swollen. The swollen leaf base is called pulvinus.
In molluscs, feather-like gills are present in mantle cavity. These gills have respiratory and excretory functions.
In $NH_3, N$ is $sp^3$ hybridised but bond angle is $107^{\circ}$. Shape of $NH_{3}$ molecule is trigonal pyramidal.
In pigeons, females are heterogametic and males are homogametic. In pigeons, females have $ZW$ sex chromosomes and males have $ZZ$ sex chromosomes.
In Rutherford?? $\alpha$ -particle scattering experiment, most of the $\alpha$ -particles were deflected by nearly $180^{\circ}$. The positive charge of the atom is spread throughout the atom that repelled and deflected the positively charged $\alpha$-particles.
In imbricate aestivation, out of five petals, one is completely internal, one is completely external and in each of the remaining three petals, one margin is internal and the other is external. Ascending imbricate aestivation is found in Cassia and gulmohur.
: In interference and diffraction, light energy is redistributed. : There is no gain or loss of energy, which is consistent with the principle of conservation of energy.
In malaria, a person experiences chills and high fever recurring every three to four days. This is caused by the release of haemozoin with rupture of liver cells.
In hydrogen and hydrogen like species, orbital energy depends only on the quantum number $n$ whereas in multi-electron atoms it depends on quantum numbers $n$ and $I$. The principal quantum number determines the size and the energy of the orbital.
In Griffith's experiment, a mixture of heat- killed virulent bacteria $R$ and live non-virulent bacteria $S$, lead to the death of mice. 'Transforming principle' got transferred from heat-killed $R$ strain to $S$ strain and made it virulent.
In change of state from solid to liquid the temperature decreases until the entire amount of the solid substance melts. The phenomenon of refreezing is called melting.
In crystalline solids, the value of resistance is different in different directions. Crystalline solids are isotropic in nature.
In cymose tap root system, oldest branch lies very near the growing point of the root while the youngest branch is farthest away from it. In cymose tap root system, the primary root itself stops growing after some time', but secondary roots carry on further growth of the root system.
In dicot stem, endodermis is also called as starch sheath. The cells of the endodermis are rich in starch grains.
In a perfectly inelastic collision the kinetic energy is never conserved. The objects get deformed and stick together in perfectly inelastic collision.
In angiosperms, endosperm development precedes embryo development. Double fertilisation ensures that the nutritive tissue is formed before the zygote starts cleaving so that the energy spent on the formation of endosperm does not get wasted.
In $C_{4}$ plants, photorespiration does not occur. $C_{4}$ plants have a mechanism that increases the concentration of $CO_{2}$ at the enzyme site.
Hydrolysis of ester is an example of auto catalytic reaction. A catalyst speeds up the process without participating in the mechanism.
Hydrophily constitutes a major mode of pollination in most of the aquatic angiospermous plants. Almost all the aquatic dicot and monocot plants require water for the transport of male gametes and for fertilisation.
Herbivores are also called as key industry animals because they convert plant matter into animal matter. Decomposers play a pivotal role in the ecosystem and they indirectly support the producers.