List of top Questions asked in JEE Main

Select the correct statement regarding compounds P, Q, R, S. 
Structures: P = Acetophenone, Q = Phenylacetaldehyde, R = Cinnamyl alcohol, S = Acetophenone. 

 

Statement (A): Resonating structure with more $\sigma$-bonds charges far apart are more stable.
Statement (B): Unsaturated hydrocarbon shows +I or –I depending upon the group they are attached with.
Statement (C): Carbanion with more % s character are more stable.
Statement (D): In nucleophilic addition to carbonyl group –E (electron-withdrawing) effect is responsible while in electrophilic additions +E is responsible.
Statement (E): Alkene having more alkyl groups have more heat of hydrogenation.
How many statements are correct?
Which of the following are {insoluble in alkali} when reacted with Hinsberg reagent?
Find correct order of acidic strength in the following reaction products \(P, Q, R \& S\):
When a nitro group is attached to a benzene ring, what effect do we observe towards reactions:

[(I)] Deactivating towards electrophilic substitution
[(II)] Activating towards electrophilic substitution
[(III)] Deactivating towards nucleophilic substitution
[(IV)] Activating towards nucleophilic substitution
Find the correct statements:
An organic compound contains C, H and O. 0.25 g of organic compound on combustion produces CO$_2$(g) and H$_2$O(l). When residual gases pass through KOH solution, its mass increases by 0.18 g and when passed through anhydrous CaCl$_2$, the increase in mass of CaCl$_2$ is 0.15 g. Find the mass % of oxygen in the organic compound.
Aniline (9.3 g) on reaction with acetic anhydride forms X (11 g). Find the percentage yield of the reaction.
Statement-I : $\text{CH}_2=\text{CH}-\text{Cl}$ is having stronger $\text{C}-\text{Cl}$ bond then $\text{CH}_3-\text{CH}_2-\text{Cl}$.
Statement-II : $\text{Ph}-\text{C}(\text{Et})(\text{Me})-\text{Cl}$ will rotate the plane polarised light after solvation.
Match the list-I and list-II name of reagent.
List-I (1) Baeyer's reagent
(2) Cerric Ammonium nitrate
(3) Tollen's reagent
(4) Neutral FeCl$_3$
List-II (P) Violet colour
(Q) Red
(R) Silver mirror
(S) Pink colour disappears
Observe the following reaction sequence:
\[ \text{C}_4\text{H}_8 \xrightarrow{\text{HCl}} \text{C}_4\text{H}_7\text{Cl} \xrightarrow{\text{NH}_3} \text{C}_4\text{H}_9\text{NH}_2 \xrightarrow{\text{NaNO}_2 + \text{HCl}} \text{C}_4\text{H}_9\text{OH} \] Which of the following is the correct structure for A, B, and C?
Given the reaction sequence:
The percentage of Nitrogen in compound E is:
Correct order of stability is :
An organic compound \(A\) with molecular formula \( \mathrm{C_4H_8O} \) gives a positive iodoform test and on oxidation forms a compound \(B\) which does not reduce Tollens' reagent. Identify compound \(A\).
(X) \(\text{NH}_3\), \(\Delta\) \(\longrightarrow\) (A)
(i) KOH + Br$_2$
(ii) CHCl$_3$, NaOH
X will be:
All possible isomers of C$_3$H$_7$Br when reacted with aq. KOH. Find out total number of optically active products (without rearrangement).
In ‘S’ estimation, \(0.314\,\text{g}\) of an organic compound gave \(0.4813\,\text{g}\) of barium sulphate. What is the percentage (%) of sulphur in the organic compound? (Report to nearest integer)
Correct sequence of reagent for the given reaction:
Consider the following anions: (i) $\text{CH}_3-\text{CH}_2^-$, (ii) $\text{CH}_2=\text{CH}^-$, (iii) $\text{HC}\equiv\text{C}^-$. Correct stability order of given anions is

Find work done in bringing charge q = 3nC from infinity to point A as shown in the figure : 

Three very long parallel wires carrying current as shown. Find the force acting at 15 cm length of middle wire : 

A circular coil of radius R carries current such that magnetic field at its centre is 16\(\mu\)T. Find the magnetic field on the axis at a distance of \(\sqrt{3}R\) from the centre of coil.
For a circular coil of radius \(R\), magnetic field at the center is \(B_0 = 16~\mu\text{T}\). What will be the magnetic field on the axis at a distance \(x = \sqrt{3}R\) from the center?
An ideal solenoid is kept with its axis vertical. Current $I_0$ is flowing in the solenoid. A charge $Q$ is thrown downward inside the solenoid. The acceleration of the charged particle is then
A bar magnet is kept such that it is making an angle of 30$^\circ$ with the magnetic field. The torque acting on the magnet is 0.016 N-m. Find the amount of work done by external agent in rotating the magnet from most stable position to most unstable position.

The intensity at spherical surface due to an isotropic point source placed at its center is $I_0$. If its volume is increased by $8$ times, what will be intensity at the spherical surface?