List of top Questions asked in JEE Main

In a nuclear fission reaction of an isotope of mass \( M \), three similar daughter nuclei of the same mass are formed. The speed of a daughter nuclei in terms of mass defect \( \Delta M \) will be:

Ice at temperature –10°C is converted to steam at 100°C, the curve plotted between temperature (T) and time (t) when it is being heated by constant power source is

Select the option with correct property -

For the photoelectric effect, the maximum kinetic energy \( E_k \) of the photoelectrons is plotted against the frequency \( \nu \) of the incident photons as shown in figure. The slope of the graph gives

A block of mass 1 kg is pushed up a surface inclined to horizontal at an angle of 60° by a force of 10 N parallel to the inclined surface as shown in the figure. When the block is pushed up by 10 m along the inclined surface, the work done against frictional force is:

If 50 Vernier divisions are equal to 49 main scale divisions of a travelling microscope and one smallest reading of the main scale is 0.5 mm, the Vernier constant of the travelling microscope is:

The variance \(\sigma^2\) of the data

Is _______.

 

A small liquid drop of radius R is divided into 27 identical liquid drops. If the surface tension is T, then the work done in the process will be :

In an a.c. circuit, voltage and current are given by:\[V = 100 \sin (100 \, t) \, \text{V}\]and\[I = 100 \sin \left(100 \, t + \frac{\pi}{3}\right) \, \text{mA}\]respectively. The average power dissipated in one cycle is:

Which of the following acts as a strong reducing agent? (Atomic number : Ce = 58, Eu = 63, Gd = 64, Lu = 71)

Identify the reagents used for the following conversion

The product A formed in the following reaction is:

On passing a gas, ‘X’, through Nessler’s reagent, a brown precipitate is obtained. The gas ‘X’ is

$\textbf{Match List I with List II}$
$\begin{array}{|c|c|c|} \hline \text{List I (Spectral Series for Hydrogen)} & \text{List II (Spectral Region/Higher Energy State)} \\ \hline \text{A. Lyman} & \text{I. Infrared region} \\ \text{B. Balmer} & \text{II. UV region} \\ \text{C. Paschen} & \text{III. Infrared region} \\ \text{D. Pfund} & \text{IV. Visible region} \\ \hline \end{array}$
$\text{Choose the correct answer from the options given below :-}$

Phenol treated with chloroform in presence of sodium hydroxide, which further hydrolysed in presence of an acid results

A reagent which gives brilliant red precipitate with Nickel ions in basic medium is

A plane is in level flight at constant speed and each of its two wings has an area of 40 m² . If the speed of the air is 180 km/h over the lower wing surface and 252 km/h over the upper wing surface, the mass of the plane is ________kg. (Take air density to be 1 kg m^–3 and g = 10 ms^–2

Let \(α\) and \(β\) the roots of equation \(px^2 + qx - r = 0\), where \(P≠ 0\). If \(p,q,r\) be the consecutive term of non constant G.P and \(\frac{1}{α} + \frac{1}{β} = \frac{3}{4}\) then the value of \((α - β)^2\) is:

Let \( \frac{x^2}{a^2} + \frac{y^2}{b^2} = 1 \), where \( a>b \), be an ellipse whose eccentricity is \( \frac{1}{\sqrt{2}} \) and the length of the latus rectum is \( \sqrt{14} \). Then the square of the eccentricity of \( \frac{x^2}{a^2} - \frac{y^2}{b^2} = 1 \) is:

Which of the following reaction is correct ?

$\textbf{Match List I with List II}$
$\begin{array}{|c|c|c|} \hline \text{List I (Compound)} & \text{List II (p}K_a\text{ value)} \\ \hline \text{A. Ethanol} & \text{I. } 10.0 \\ \text{B. Phenol} & \text{II. } 15.9 \\ \text{C. m-Nitrophenol} & \text{III. } 7.1 \\ \text{D. p-Nitrophenol} & \text{IV. } 8.3 \\ \hline \end{array}$
$\text{Choose the correct answer from the options given below :-}$

$\textbf{Match List I with List II}$
$\begin{array}{|c|c|c|} \hline \text{List I (Bio Polymer)} & \text{List II (Monomer)} \\ \hline \text{A. Starch} & \text{I. nucleotide} \\ \text{B. Cellulose} & \text{II. } \alpha\text{-glucose} \\ \text{C. Nucleic acid} & \text{III. } \beta\text{-glucose} \\ \text{D. Protein} & \text{IV. } \alpha\text{-amino acid} \\ \hline \end{array}$
$\text{Choose the correct answer from the options given below :-}$

The ascending acidity order of the following H atoms is

A particle is moving in a circle of radius 50 cm in such a way that at any instant the normal and tangential components of its acceleration are equal. If its speed at \( t = 0 \) is \( 4 \, \text{m/s} \), the time taken to complete the first revolution will be\[\frac{1}{\alpha} \left[ 1 - e^{2\pi} \right] \, \text{s},\]where \( \alpha = \, \underline{\hspace{2cm}} \).

N moles of a polyatomic gas (f = 6) must be mixed with two moles of a monoatomic gas so that the mixture behaves as a diatomic gas. The value of N is :