List of top Questions asked in NEET (UG)

A $p-n$ photodiode is made of a material with a band gap of $2\, eV$. The minimum frequency of the radiation that can be absorbed by the material is nearly (he = 1240 eV nm)
On a new scale of temperature (which is linear) and called the W scale, the freezing and boiling points of water are 39$^{\circ}$W and 239$^{\circ}$W respectively. What will be the temperature on the new scale, corresponding to a temperature of 39$^{\circ}$C on the Celsius scale?
On the basis of the following $E^0 $ values, the strongest oxidising agent is $[Fe(CN)_6]^{4-} \rightarrow [Fe(CN)_6]^{3-}+e^-; $ $\hspace15mm E^0=-0.35 V $ $Fe^{2+} \rightarrow Fe^{3+} + e^-;E^0=-0.77 V $
Two nuclei have their mass numbers in the ratio of 1 : 3. The ratio of their nuclear densities would be
The rate constants $k_1$ and $k_2$ for two different reactions are $10^{16} .e^{-2000/T}$ and $10^{15} .e^{-1000/T}$,respectively. The temperature at which $k_1= k_2$ is
In which of the following coordination entities the magnitude of $\Delta_0$ (CFSE in octahedral field) will be maximum? (At. no. of Co = 27)
-The stability of carbanions in the following (i) $RC \equiv {C}^{\ominus}$ (iii) $R_2C = {CH}^{\ominus}$ (iv) $R_3C = {CH_2}^{\ominus}$ , is in the order of
A cell can be balanced against 110 cm and 100 cm of potentiometer wire, respectively with and without being short circuited through a resistance of $10\, \Omega.$ Its internal resistance is
A wire of a certain material is stretched slowly by ten percent. Its new resistance and specific resistance become respectively
An organic compound contains carbon, hydrogen and oxygen. Its elemental analysis gave C, 38.71% and H, 9.67%. The empirical formula of the compound would be
Bond dissociation enthalpy of ${H_2, Cl_2}$ and $HCl$ are $434, 242$ and ${431 \, kJmol^{- 1}}$ respectively. Enthalpy of formation of $HCl $ is
For the gas phase reaction, ${PCl_{5} (g) <=> PCl_{3} (g) + Cl_{2} (g)}$ which of the following conditions are correct ?
The correct order of decreasing second ionisation enthalpy of Ti(22), V(23), Cr(24) and Mn(25) is
Equimolar solutions of the following were prepared in water separately. Which one of the solutions will record the highest pH ?
Which one of the following is an amine hormone?
How many stereoisomers does this molecule have? $CH_3CH = CHCH_2CHBrCH_3$
The relative reactivities of acyl compounds towards nucleophilic substitution are in the order of
A strong base can abstract an $\alpha$-hydrogen from
Number of moles of $MnO^{-}_4$ required to oxidise one mole of ferrous oxalate completely in acidic medium will be
A particle shows distance - time curve as given in this figure. The maximum instantaneous velocity of the particle is around the point
An electric kettle takes 4 A current at 220 V. How much time will it take to boil 1 kg of water from temperature $20^\circ C ?$ The temperature of boiling water is $100^\circ C $
A current of 3 amp. flows through the $2\, \Omega$ resistor shown in the circuit. The power dissipated in the $5\, \Omega$ resistor is
The angular shape of ozone molecule $ (O_3 )$ consists of
In the reaction; $Fe ( OH )_{3( s )} \rightleftharpoons Fe ^{3+}{ }_{( aq )}+3 OH _{\text {(aq) }}^{-}$, if the concentration of $OH ^{-}$ ions is decreased by $\frac{1}{4}$ times, then the equilibrium concentration of $Fe ^{3+}$ will increase by,
The value of equilibrium constant of the reaction, $ HI(g) \rightleftharpoons \frac{1}{2} H_2 (g) + \frac{1}{2} I_2 (g)\, \, is\, \, 8.0 $ . The equilibrium constant of the reaction, $ H_2 (g) + I_2 (g) \rightleftharpoons 2HI(g) $ Will be