List of top Questions asked in JEE Main

Which of the following reaction/s will not give \(p-\) aminoazobenzene?

In the given figure, the energy levels of hydrogen atom have been shown along with some transitions marked $A , B , C , D$ and $E$. The transitions $A, B$ and $C$ respectively represent :

Four identical particles of equal masses $1 kg$ made to move along the circumference of a circle of radius $1 m$ under the action of their own mutual gravitational attraction. The speed of each particle will be :

If an emitter current is changed by $4 mA ,$ the collector current changes by $3.5 mA$. The value of $\beta$ will be

Each side of a box made of metal sheet in cubic shape is 'a' at room temperature 'T', the coefficient of linear expansion of the metal sheet is ' $\alpha^{\prime}$. The metal sheet is heated uniformly, by a small temperature $\Delta T ,$ so that its new temperature is $T +\Delta T$. Calculate the increase in the volume of the metal box.

A cube of side 'a' has point charges \(+ Q\) located at each of its vertices except at the origin where the charge is \(-Q\). The electric field at the centre of cube is:

If $Y, K$ and $\eta$ are the values of Young's modulus, bulk modulus and modulus of rigidity of any material respectively. Choose the correct relation for these parameters.

Two equal capacitors are first connected in series and then in parallel. The ratio of the equivalent capacities in the two cases will be:

An LCR circuit contains resistance of $110 \Omega$ and a supply of $220 V$ at $300 rad / s$ angular frequency. If only capacitance is removed from the circuit, current lags behind the voltage by $45^{\circ} .$ If on the other hand, only inductor is removed the current leads by $45^{\circ}$ with the applied voltage. The $rms$ current flowing in the circuit will be :

Calgon is used for water treatment. Which of the following statement is $NOT$ true about Calgon?

Statements about heavy water are given below A. Heavy water is used in exchange reactions for the study of reaction mechanisms B. Heavy water is prepared by exhaustive electrolysis of water C. Heavy water has higher boiling point than ordinary water D. Viscosity of $H _{2} O$ is greater than $D _{2} O$

Given below are two statements : Two photons having equal linear momenta have equal wavelengths. If the wavelength of photon is decreased, then the momentum and energy of a photon will also decrease. In the light of the above statements, choose the correct answer from the options given below.

In Freundlich adsorption isotherm, slope of AB line is :

The correct order of bond dissociation enthalpy of halogens is :

Which of the following are isostructural pairs? A. $SO _{4}^{2-}$ and $CrO _{4}^{2-}$ B. $SiCl _{4}$ and $TiCl _{4}$ C. $NH _{3}$ and $NO _{3}^{-}$ D. $BCl _{3}$ and $BrCl _{3}$ $BCl _{3}$ and $BrCl _{3}$

What is the major product formed by $HI$ on reaction with

According to molecular theory, the species among the following that does not exist is:

If the velocity-time graph has the shape AMB, what would be the shape of the corresponding acceleration-time graph ?

A possible value of $\tan \left(\frac{1}{4} \sin ^{-1} \frac{\sqrt{63}}{8}\right)$ is :

The vector equation of the plane passing through the intersection of the planes $\vec{ r } .(\hat{ i }+\hat{ j }+\hat{ k })=1$ and $\vec{ r } .(\hat{ i }-2 \hat{ j })=-2,$ and the point (1,0,2) is :

The angle of elevation of a jet plane from a point A on the ground is $60^{\circ}$. After a flight of 20 seconds at the speed of $432 km /$ hour, the angle of elevation changes to $30^{\circ} .$ If the jet plane is flying at a constant height, then its height is :

Let $f: R \rightarrow R$ be defined as, $f(x) = \begin{cases} -55x, & \text{if } x < -5 \\ 2x^3 -3x^2 -120x, & \text{if } 5 \le x \le 4 \\ 2x^3 -3x^2-36x-336& \text{if } x > 4, \end{cases} $ Let $A=\{ x \in R : f$ is increasing $\} .$ Then $A$ is equal to

Let $R =\{( P , Q ) | P$ and $Q$ are at the same distance from the origin $\}$ be a relation, then the equivalence class of (1,-1) is the set:

The period of oscillation of a simple pendulum is $T =2 \pi \sqrt{\frac{ L }{ g }}$. Measured value of 'L' is $1.0 m$ from meter scale having a minimum division of $1 mm$ and time of one complete oscillation is 1.95 s measured from stopwatch of $0.01 s$ resolution. The percentage error in the determination of 'g' will be :