List of top Physics Questions asked in JEE Main

For a charged spherical ball, electrostatic potential inside the ball varies with 𝑟 as $V=2𝑎𝑟^2+𝑏$. Here, 𝑎 and 𝑏 are constant and r is the distance from the center. The volume charge density inside the ball is −𝜆𝑎𝜀. The value of 𝜆 is ______.
(𝜀= permittivity of the medium)

A body of mass $10 kg$ is moving with an initial speed of $20 m / s$ The body stops after $5 s$ due to friction between body and the floor The value of the coefficient of friction is: (Take acceleration due to gravity $g =10 ms ^{-2}$ )

The time period of a satellite of earth is 24 hours. If the separation between the earth and the satellite is decreased to one fourth of the previous value, then its new time period will become.

For the given figures, choose the correct options:

The rms current in circuit (b) can never be larger than that in (a)

A microscope is focused on an object at the bottom of a bucket If liquid with refractive index $\frac{5}{3}$ is poured inside the bucket, then microscope have to be raised by $30\, cm$ to focus the object again The height of the liquid in the bucket is :

Heat energy of 184 kJ is given to ice of mass $600 g$ at −12°C. Specific heat of ice is $ 2222.3 J kg^{−1}C^{−1}$ and latent heat of ice in $ 336 kJkg^{−1} $
A. Final temperature of system will be 0°C.
B. Final temperature of the system will be greater than 0°C.
C. The final system will have a mixture of ice and water in the ratio of 5:1.
D. The final system will have a mixture of ice and water in the ratio of 1:5.
E. The final system will have water only.
Choose the correct answer from the options given below:

A scientist is observing a bacteria through a compound microscope. For better analysis and to improve its resolving power he should. (Select the best option)

A point charge $2×10^{−2}C$ is moved from P to S in a uniform electric field of $30NC^{−1}$ directed along positive x-axis. If coordinates of P and S are $(1,2,0) m $ and $(0,0,0) m$ respectively, the work done by electric field will be

A body weight W, is projected vertically upwards from earth's surface to reach a height above the earth which is equal to nine times the radius of earth The weight of the body at that height will be :

An object moves at a constant speed along a circular path in a horizontal plane with center at the origin. When the object is at =+2 m, its velocity is $−4\hat{j}m/s$. The object's velocity (v) and acceleration (𝑎) at 𝑥=−2 m will be

A fully loaded boeing aircraft has a mass of $5.4×10^5 $ kg. Its total wing area is $500 m^2$. It is in level flight with a speed of 1080 km/h. If the density of air 𝜌 is $1.2 kg m^{−3}$, the fractional increase in the speed of the air on the upper surface of the wing relative to the lower surface in percentage will be. ($𝑔=10 m/s^2$)

A force acts for 20 s on a body of mass 20 kg, starting from rest, after which the force ceases and then body describes 50 m in the next 10 s. The value of force will be:

The time taken by an object to slide down 45° rough inclined plane is n times as it takes to slide down a perfectly smooth 45° incline plane. The coefficient of kinetic friction between the object and the incline plane is:

Heat energy of 735J is given to a diatomic gas allowing the gas to expand at constant pressure Each gas molecule rotates around an internal axis but do not oscillate The increase in the intemal energy of the gas will be :

For the given logic gates combination, the correct truth table will be

The ratio of de-Broglie wavelength of an $\alpha$ particle and a proton accelerated from rest by the same potential is $\frac {1}{\sqrt 𝑚}$ , the value of $m$ is-

At $300 K$ the rms speed of oxygen molecules is $\sqrt {\frac {\alpha+5}{\alpha}}$ times to that of its average speed in the gas. Then, the value of $\alpha$ will be
(used $\pi=\frac {22}{7}$)

Substance A has atomic mass number 16 and half-life of 1 day. Another substance 𝐵 has atomic mass number 32 and half life of $\frac1{ 2}$ day. If both 𝐴 and 𝐵 simultaneously start undergo radio activity at the same time with initial mass 320 g each, how many total atoms of A and B combined would be left after 2 days.

An electron of a hydrogen like atom, having $Z=4$, jumps from $4^{\text {th }}$ energy state to $2^{\text {nd }}$ energy state. The energy released in this process, will be :
$($ Given Rch $=136 eV )$
Where $R =$ Rydberg constant
$c =$ Speed of light in vacuum
$h =$ Planck's constant

An atom absorbs a photon of wavelength 500 nm and emits another photon of wavelength 600 nm. The net energy absorbed by the atom in this process is n × 10^-4 eV. The value of n is____.[Assume the atom to be stationary during the absorption and emission process](Take h = 6.6 x 10^-34 js and c = 3 x 10⁸ m/s)

Three point charges q, –2q and 2q are placed on x-axis at a distance x = 0, x = $\frac{3}{ 4}$ R and x = R respectively from origin as shown. If q = 2 × 10^-6 C and R = 2 cm, the magnitude of net force experienced by the charge –2q is ________ N.

A bi-convex lens of focal length 10 cm is cut perpendicularly to principal axis.
Find Power (in D) of new lens.

A light rope is wound around a hollow cylinder of mass 5 kg and radius 70 cm. The rope is pulled with a force of 52.5 N. The angular acceleration of the cylinder will be rad s^-2

Two plates A and B have thermal conductivities 84 $Wm^{-1}K^{-1}$ and 126 $Wm^{-1}K^{-1}$ respectively. They have same surface area and same thickness. They are placed in contact along their surfaces. If the temperatures of the outer surfaces of A and B are kept at 100 °C and 0 ºC respectively, then the temperature of the surface of contact in steady state is ________°C.

A vessel of depth 'd' is half filled with oil of refractive index n₁ and the other half is filled with water of refractive index n₂. The apparent depth of this vessel when viewed from above will be-