List of top Physics Questions asked in JEE Main

The distance of centre of mass from end \(A\) of a one dimensional rod (\(AB\)) having mass density \(ρ=ρ_0(1-\frac{x^2}{L^2})kg/m\) and length L. (in meter) is \(\frac{3L}{α} m\). The value of \(α\) is......... (where \(x\) is the distance form end \(A\))

A spherical shell of 1 kg mass and radius R is rolling with angular speed ω on horizontal plane (as shown in figure). The magnitude of angular momentum of the shell about the origin O is \(\frac{a}{3}R^2w\). The value of a will be

A spherical shell of 1 kg mass and radius R is rolling with angular speed

Two capacitors, each having capacitance $40 \mu F$ are connected in series The space between one of the capacitors is filled with dielectric material of dielectric constant $K$ such that the equivalence capacitance of the system became $24 \mu F$ The value of $K$ will be :
Two projectile thrown at $30^{\circ}$ and $45^{\circ}$ with the horizontal respectively, reach the maximum height in same time The ratio of their initial velocities is
A screw gauge of pitch $05 \,mm$ is used to measure the diameter of uniform wire of length $68 \,cm$, the main scale reading is $15\, mm$ and circular scale reading is $7$. The calculated curved surface area of wire to appropriate significant figures is :[Screw gauge has $50$ divisions on the circular scale]
The force required to stretch a wire of cross-section $1 cm ^2$ to double its length will be: (Given Yong's modulus of the wire $=2 \times 10^{11} N / m ^2$ )
If the radius of earth shrinks by $2 \%$ while its mass remains same The acceleration due to gravity on the earth's surface will approximately :
In two different experiments, an object of mass $5\, kg$ moving with a speed of $25 \,ms ^{-1}$ hits two different walls and comes to rest within
(i) 3 second, 
(ii) 5 seconds, respectively.
Choose the correct option out of the following :
 NCC parade is going at a uniform speed of $9\, km / h$ under a mango tree on which a monkey is sitting at a height of $196\, m$ At any particular instant, the monkey drops a mango A cadet will receive the mango whose distance from the tree at time of drop is : (Given g= 9.8 m/s2)
The dimensions of $\left(\frac{ B ^2}{\mu_0}\right)$ will be :(if $\mu_0$ : permeability of free space andB : magnetic field)

a block of mass m slides on the wooden wedge which in turn slides backward on the horizontal surface. The acceleration of the block with respect to the wedge is: 
[ Given m= 8kg, M=16kg ]
[Assume all the surfaces shown in the figure to be frictionless] 
 

Two equal capacitors are first connected in series and then in parallel. The ratio of the equivalent capacities in the two cases will be:
If the velocity-time graph has the shape AMB, what would be the shape of the corresponding acceleration-time graph ?
Match List -I with List -II
List - I List -II
a Isothermal i Pressure constant
b Isobaric ii Temperature constant
c Adiabatic iii Volume constant
d Isobaric iv Heat content is constant
Choose the correct answer from the options given below
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.
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
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:
A cube of side 'a' has point charges +Q located at each of its vertices except at the origin where the charge is −Q
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 :
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.
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 :
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.
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 :
A small object is placed at the center of a large evacuated hollow spherical container. Assume that the container is maintained at $0\, K$. At time $t =0$, the temperature of the object is $200 \,K$. The temperature of the object becomes $100 \,K$ at $t = t _{1}$ and $50\, K$ at $t = t _{2}$.Assume the object and the container to be ideal black bodies. The heat capacity of the object does not depend on temperature. The ratio \(\left( \frac{t _{2} }{ t _{1}}\right)\) is______

Two small spheres each of mass 10 mg are suspended from a point by threads 0.5 m long. They are equally charged and repel each other to a distance of 0.20 m. The charge on each of the sphere is \(\frac{a}{21} \times 10^{-8} C\). 
The value of 'a' will be ______. [Given g = 10 ms–2]