List of top Questions asked in JEE Main- 2015

In the electric network shown, when no current flows through the $4\, \Omega$ resistor in the arm $EB$, the potential difference between the points $A$ and $D$ will be :

When $5\,V$ potential difference is applied across a wire of length $0.1\,m$, the drift speed of electrons is $2.5\times10^{-4}$ $ms^{-1}$. If the electron density in the wire is $8\times10^{28}\, m^{-3}$ the resistivity of the material is close to

The ionic radii (in $?$) of $N^{3-},O^{2-} $ and $F^-$ respectively are

The number of geometric isomers that can exist for square planar $\left[ Pt ( Cl )( py )\left( NH _{3}\right)\right.$ $\left.\left( NH _{2} OH \right)\right]^{+}$ is $( py =$ pyridine $):$

Which artificial sweetener contains chlorine ?

Consider a spherical shell of radius $R$ at temperature $T$. The black body radiation inside it can be considered as an ideal gas of photons with internal energy per unit volume $u=\frac{U}{V} ? T^4$ and pressure $p=\frac{1}{3}\bigg(\frac{U}{V}\bigg)$ If the shell now undergoes an adiabatic expansion, the relation between $T$ and $R$ is

Consider an ideal gas confined in an isolated closed chamber. As the gas undergoes an adiabatic expansion, the average time of collision between molecules increases as $V^q$ , where $V$ is the volume of the gas. The value of $q$ is $\bigg(\gamma =\frac{C_p}{C_v}\bigg)$

A solid body of constant heat capacity $1 \, J/^{\circ}C$ is being heated by keeping it in contact with reservoirs in two ways (i) Sequentially keeping in contact with $2$ reservoirs such that each reservoir supplies same amount of heat. (ii) Sequentially keeping in contact with $8$ reservoirs such that each reservoir supplies same amount of heat. In both the cases, body is brought from initial temperature $100^{\circ}C$ to final temperature $200^{\circ}C$. Entropy change of the body in the two cases respectively, is

As an electron makes a transition from an excited state to the ground state of a hydrogen- like atom/ion

A long cylindrical shell carries positive surface charge $\sigma$ in the upper half and negative surface charge $-\sigma$ in the lower half. The electric field lines around the cylinder will look like figure given in: (figures are schematic and not drawn to scale)

A thin disc of radius $b\, = \,2a$ has a concentric hole of radius '$a$' in it (see figure). It carries uniform surface charge '$\sigma$' on it. If the electric field on its axis at height '$h$' $(h < < a)$ from its centre is given as '$Ch$' then value of '$C$' is :

Higher order $( > 3 )$ reactions are rare due to

Which of the following compounds is not colored yellow?

The area (in s units) of the quadrilateral formed by the tangents at the end points of the latera recta to the ellipse $\frac{x^{2}}{9}+\frac{y^{2}}{5}=1$, is:

The correct order of thermal stability of hydroxides is :

Photochemical smog consists of excessive amount of $X$, in addition to aldehydes, ketones, peroxyacetyl nitrile $(PAN)$, and so forth. $X$ is :

Which polymer is used in the manufacture of paints and lacquers?

A short bar magnet is placed in the magnetic meridian of the earth with north pole pointing north. Neutral points are found at a distance of $30 \,cm$ from the magnet on the East - West line, drawn through the middle point of the magnet. The magnetic moment of the magnet in $Am^2$ is close to : (Given $\frac{\mu_{0}}{4\pi}=10^{-7}$ in SI units and $B_H$ = Horizontal component of earth's magnetic field = $3.6 \times 10^{-5}$ Tesla.)

Which among the following is the most reactive?

The value of $\int \limits \frac {dx}{x^2(x^4+1)^{3/4}}$ is

Calamine is an ore of :

Assuming human pupil to have a radius of $0.25\, cm$ and a comfortable viewing distance of $25\, cm$, the minimum separation between two objects that human eye can resolve at $500\, nm$ wavelength is

In the context of the Hall-Heroult process for the extraction of $Al$, which of the following statements is false?

If $f\left(x\right) = 2 \tan^{-1} x + \sin^{-1} \left(\frac{2x}{1+x^{2}}\right), x > 1$, then $f(t)$ is equal to :

Which of the following compounds is not an antacid?