List of top Questions asked in JEE Main

Ratio between rms speed of Ar to the most probable speed of \(O^2\) at \(27\degree C\) is

Let A=\(\begin{bmatrix} 1 & \frac{1}{51} \\ 0 & 1\end{bmatrix}\). If B=\(\begin{bmatrix} 1 & 2 \\ -1 & -1\end{bmatrix}\)A \(\begin{bmatrix} -1 & -2 \\ 1 & 1\end{bmatrix}\), then the sum of all the elements of the matrix \(\sum^{50}_{n=1}B^n\) is equal to

Assuming the earth to be a sphere of uniform mass density, the weight of a body at a depth \(d=\frac{R}{2}\) from the surface of earth, if its weight on the surface of earth is 200 N, will be 

Find the equivalent resistance across A and B for given circuit.

A radioactive nuclei X decays simultaneously to two nuclei Y and Z as:

t_½ is 12 minutes while t'_½ is 3 minutes. Find the time in which nuclei X decays 50%.

\(tan^{-1}(\frac {1+\sqrt 3}{3+\sqrt 3})+sec^{-1}(\sqrt {\frac {8+4\sqrt 3}{3+3\sqrt 3})}\) is equal to:

Pick the correct graph between potential V at distance r from centre for the uniformly charged spherical shell of radius R.
 

α-particle, proton & electron have same kinetic energy. Select correct order of their de-Broglie wavelength.

Mass of body = 500 kg,  μ= 0.7. Find work required to move a distance of 4 Km if the body moves with velocity 10 m/s.

Statement (1): A truck and a car moving with equal kinetic energy are stopped by equal retarding force. Both will cover equal distance to stop.
Statement (2): A car moving towards east suddenly changes its direction towards north with same speed. Its acceleration is zero.
In the light of given statements, choose the most appropriate answer from the options given below.

Match the physical quantity in column-I with the respective dimension in column-II and choose the correct option.

The length of a conductor having resistance 160 Ω, is compressed to 25% of its initial value. The new resistance will be

Statement I : In LCR circuit, by increasing frequency current increases first then decreases.
Statement II : Power factor of LCR circuit is one.
Choose the correct option.

Assertion (A): An electrical dipole is enclosed in a closed gaussian surface. The total flux through the enclosed surface is zero. 
Reason (R): Net charge inside the enclosed surface is zero.

A circular ring is placed in magnetic field of 0.4 T. Suddenly its radius starts shrinking at the rate of 1 mm/s. Find the induced emf in the ring at r = 2 cm.

A body is doing SHM with amplitude A. When it is at \( x =+ \frac{A}{2}\) , find ratio of kinetic energy to potential energy.

Bob P is released from the position of rest at the moment shown. If it collides elastically with an identical bob Q hanging freely then velocity of Q, just after collision is (g = 10 m/s²).

Position-time graph for a particle is parabolic and is as shown:

Choose the corresponding v – t graph.

For a system undergoing isothermal process, heat energy is supplied to the system. Choose the option showing correct statements
(a) Internal energy will increase
(b) Internal energy will decrease
(c) Work done by system is positive
(d) Work done by system is negative
(e) Internal energy remains constant

The heat passing through the cross-section of a conductor, varies with time ‘t’ as \(Q(t) = αt – βt^2 + γt^3\). (\(α, β\) and \(γ\) are positive constants.) The minimum heat current through the conductor is

Momentum-time graph of an object moving along a straight line is as shown in figure. If (P₂ – P₁) < P₁ and (t₂ – t₁) = t₁ < (t₃ – t₂) then at which points among A, B and C the magnitude of force experienced by the object is maximum and minimum respectively.

A particle moving in unidirectional motion travels half of the total distance with a constant speed of 15 m/s. Now first half of the journey time it travels at 10 m/s and second half of the remaining journey time it travels at 5 m/s. Average speed of the particle is

A bullet strikes a stationary ball kept at a height as shown. After collision, range of bullet is 120 m and that of ball is 30 m. Find initial speed of bullet. Collision is along horizontal direction. 
(Take g = 10 m/s²)