List of top Questions asked in AIIMS

Histones are basic protein of major importance in packaging of eukaryotic $DNA. DNA$ and histone comprise chromatine forming bulk of eukaryotic chromosome. Histones are five major types $H_{l},\, H_{2}A,\, H_{2}B,\, H_{3}\, and\, H_{4}$.
HC $=$ C$^{-}$ is more stable than HC $=$ CH$^{-}$. HC $=$ C$^{-}$ has more s-character than HC $=$ CH$^{-}$.
$H_2Se$ is less acidic than $H_2S$. $S$ is less electronegative than $Se$.
$[Fe(H_2O)_5NO]SO_4$ is paramagnetic. The $Fe$ in $[Fe(H_2O)_5NO]SO_4$ has three unpaired electrons.
Diamond and graphite do not have the same crystal structure. Diamond is crystalline while graphite is amorphous.
$ClF_3$ has T-shape structure. It has two lone pairs arranged at 180$^{\circ}$ angle.
$BF_3$ molecule is planar but $NF_3$ is pyramidal. N atom is smaller than B.
AIDS is caused by the HIV, a retrovirus. Retroviruses have RNA genome.
Apiculture is associated with which of the following groups of plants?
An artificial satellite moving in a circular orbit around the earth has a total (kinetic $+$ potential) energy $E_0$. Its potential energy is
Four successive members of the first row transition elements are listed below with their atomic numbers. Which one of them is expected to have the highest third ionization enthalpy?
What is the correct relationship between the $pHs$ of isomolar solutions of sodium oxide $(pH_1)$, sodium sulphide $(pH_2)$, sodium selenide $(pH_3)$ and sodium telluride $(pH_4)$?
The aqueous solution containing which one of the following ions will be colourless? (Atomic number of $Sc = 21, Fe = 26, Ti = 22, Mn = 25$)
Which has the highest nucleophilicity?
Of the following, the oxime of which shows geometrical isomerism is
Freon used as refrigerant is
The reduction potential at $pH = 14$ for the $Cu^{2+} /Cu$ couples is [ Given , $E^{\circ}_{Cu^{2+}}/Cu = 0.34 \,V; K_{sp} Cu(OH)_2 = 1\times 10^{-19}$
Which of the following induces parturition?
The source of taq polymerase used in PCR is a
Stomatal opening is affected by
Abscisic acid is known as the stress hormone because it
A spherical drop of capacitance 1 $\mu$F is broken into eight drops of equal radius. Then, the capacitance of each small drop is
In a set of reactions, acetic acid yielded product $ D.C{{H}_{3}}COOH\xrightarrow{SOC{{l}_{2}}}A\xrightarrow[Anhy.\,\,AlC{{l}_{3}}]{Benzene} $ $ B\xrightarrow{HCN}C\xrightarrow{HOH}D $ . The structure of $ D $ would be
The half-life of radioactive element is $600 \,yr$. The fraction of sample that would remain after $3000 \,yr$ is
In the capacitor of capacitance $C$, charge $Q$ and energy $W$ is stored. If charge is increased upto $2Q$, the energy stored will be