List of top Questions asked in NEET (UG)

Two metal rods $1$ and $2$ of same lengths have same temperature difference between their ends. Their thermal conductivities are $ K_1$ and $K_2 $ and cross sectional areas $ A_1 $ and $ A_ 2 $ respectively. If the rate of heat conduction in 1 is four times that in 2, then :

A reaction having equal energies of activation for forward and reverse reactions has :-

Consider the half-cell reduction reaction :- $Mn^{2+}+2e^{-}\to Mn, E^{0}=-1.18 V$ $Mn^{2+}\to Mn^{3+}+e^{-}, E^{0}=-1.51 V$ The $E^\circ$ for the reaction $3 Mn^{2+}\to Mn^{0}+2Mn^{3+}$ and possibility of the forward reaction are respectively :

The colonies of recombinant bacteria appear white in contrast to blue colonies of nonrecombinant bacteria because of

Artificial insemination means :

Which one of the following is one of the paths followed by air or O during respiration in the adult male Periplaneta americana as it enters the animal body?

For a normal eye, the cornea of eye provides a converging power of $40\, D$ and the least converging power of the eye lens behind the cornea is $20\, D$. Using this information, the distance between the retina and the cornea -eye lens can be estimated to be -

Arrange the following in increasing order of stability:- $\left(a\right) \left(CH_{3}\right)_{2}C^{^{\oplus}}-CH_{2}-CH_{3} \quad\left(b\right) \left(CH_{3}\right)_{3}C^{^{\oplus}}$ $\left(c\right) \left(CH_{3}\right)_{2}C^{^{\oplus}}H \quad\quad\quad\quad\quad\quad\quad\left(d\right) CH_{3} C^{^{\oplus}}H_{2}$ $\left(e\right)C^{^{\oplus}}H_{3}$

In which of the following ionization processes the bond energy increases and the magnetic behaviour changes from paramagnetic to diamagnetic :

Sc(Z = 21) is a transition element but Zn (Z = 30) is not because :

A system is taken from state $a$ to state $c$ by two paths $adc$ and $abc$ as shown in the figure. The internal energy at $a$ is $U_a=10 \, J . $ Along the path $adc$ the amount of heat heat absorbed $\delta Q_1=50\, J $ and the work obtained $\delta W_1=20 \, J $ whereas along the path $abc$ the heat absorbed $\delta Q_2=36 \, J . $ The amount of work along the path $abc$ is :

The condition under which a microwave oven heats up a food item containing water molecules most efficiently is :

A button cell used in watches function as following Zn(s) + Ag₂O(s) + H₂O(l) $\rightleftharpoons$ 2Ag(s) + Zn²⁺(aq) + 2OH^-(aq). If half cell potentials are ${Zn^{2+}_{ (aq)} + 2e\to Zn(s); E^{\circ} = -0.76V}$ ${Ag2O_{(s)} + H2O_{(l)} + 2e\to 2Ag_{(s)} + 2OH^{-}_{(aq)};}$ $E^{\circ} = 0.34V$

A wire loop is rotated in magnetic field. The frequency of change of direction of the induced e.m.f. is :

A particle of mass $m$ is kept at rest at a height $3R$ from the surface of earth, where $R$ is radius of earth and $M$ is mass of earth. The minimum speed with which it should be projected, so that it does not return back, is : (g is acceleration due to gravity on the surface of earth)

A piece of iron is heated in a flame. It first becomes dull red then becomes reddish yellow and finally turns to white hot. The correct explanation for the above observation is possible by using :

The radius of a planet is twice the radius of earth. Both have almost equal average mass-densities. $v_P$ and $v_E$ are escape velocities of the planet and the earth, respectively, then

Among the following ethers, which one will produce methyl alcohol on treatement with hot concentrated HI ?

The structure of isobutyl group in an organic compound is :-

What is the hybridisation state of benzyl carbonium ? :-

A gas is taken through the cycle $A \rightarrow B \rightarrow C \rightarrow A,$ as shown. What is the net work done by the gas?

During the process of isolation of DNA, chilled ethanol is added to :