List of top Physics Questions asked in JEE Main

The SI unit of a physical quantity is pascal-second. The dimensional formula of this quantity will be
When a ball is dropped into a lake from a height 4.9 m above the water level, it hits the water with a velocity v and then sinks to the bottom with the constant velocity v. It reaches the bottom of the lake 4.0 s after it is dropped. The approximate depth of the lake is :
A stone tied to a string of length \(L\) is whirled in a vertical circle with the other end of the string at the centre. At a certain instant of time, the stone is at its lowest position and has a speed \(u\). The magnitude of change in its velocity, as it reaches a position where the string is horizontal, is \(\sqrt{x(u^2−gL)}\). The value of \(x\) is
Three identical charged balls each of charge \(2\) \(C\) are suspended from a common point \(P\) by silk threads of \(2\) \(m\) each (as shown in figure). They form an equilateral triangle of side \(1\) \(m\). The ratio of net force on a charged ball to the force between any two charged balls will be:
Three identical charged balls each of charge 2 C are suspended from a common point P

Two long parallel conductors \(S_1\) and \(S_2\) are separated by a distance \(10\) cm and carrying currents of \(4\) A and \(2\) A respectively. The conductors are placed along x-axis in X–Y plane. There is a point P located between the conductors (as shown in figure). A charge particle of \(3π\) coulomb is passing through the point P with velocity \(\overrightarrow v=(2\hat i+3\hat j)\) m/s; where \(\hat i\) and \(\hat j\) represents unit vector along x & y axis respectively. The force acting on the charge particle is \(4π×10^{−5}(−x\hat i+2\hat j)N\). The value of x is:
The conductors are placed along x-axis in X–Y plane. There is a point P located between the conductors

Four spheres each of mass m form a square of side d (as shown in figure). A fifth sphere of mass M is situated at the centre of square. The total gravitational potential energy of the system is:
Four spheres each of mass m form a square of side d
According to kinetic theory of gases,
A. The motion of the gas molecules freezes at 0°C
B. The mean free path of gas molecules decreases if the density of molecules is increased.
C. The mean free path of gas molecules increases if temperature is increased keeping pressure constant.
D. Average kinetic energy per molecule per degree of freedom is \(\frac{3}{2}k_BT\) (for monoatomic gases).
Choose the most appropriate answer from the options given below:
If a charge q is placed at the centre of a closed hemispherical non-conducting surface, the total flux passing through the flat surface would be:
A capacitor of capacitance \(50pF\) is charged by \(100 V\) source. It is then connected to another uncharged identical capacitor. Electrostatic energy loss in the process is _____ nJ.
A lead bullet penetrates into a solid object and melts. Assuming that 40% of its kinetic energy is used to heat it, the initial speed of bullet is: (Given initial temperature of the bullet = 127°C), Melting point of the bullet = 327°C, Latent heat of fusion of lead = \(2.5 × 10^4 J kg^{–1}\) Specific heat capacity of lead = 125 J/kg K)
One end of a massless spring of spring constant k and natural length \(l_0\) is fixed while the other end is connected to a small object of mass \(m\) lying on a frictionless table. The spring remains horizontal on the table. If the object is made to rotate at an angular velocity \(ω\) about an axis passing through fixed end, then the elongation of the spring will be :
A pendulum of length \(2\ m\) consists of a wooden bob of mass \(50\ g\). A bullet of mass \(75\ g\) is fired towards the stationary bob with a speed v. The bullet emerges out of the bob with a speed \(\frac v3\) and the bob just completes the vertical circle. The value of v is _______ \(ms^{–1}\). (if \(g=10\ m/s^2\)).
For a perfect gas, two pressures \(P_1\) and \(P_2\) are shown in the figure. The graph shows:
Given below are two statements:
Statement I: A time varying electric field is a source of changing magnetic field and vice-versa. Thus a disturbance in electric or magnetic field creates EM waves.
Statement II: In a material medium, the EM wave travels with speed
\(V=\frac{1}{\sqrt{µ0ε0}}\) In the light of the above statements, choose the correct answer from the options given below.
The equation of a particle executing simple harmonic motion is given by \(x=sin\;π\bigg(t+\frac{1}{3}\bigg)m\).  At \(t = 1s\), the speed of the particle will be
The distance of the Sun from Earth is \(1.5 × 10^{11}\) \(m\), and its angular diameter is \((2000)\) \(s\) when observed from the earth. The diameter of the Sun will be :
A beam of monochromatic light is used to excite the electron in \(Li^{++}\) from the first orbit to the third orbit. The wavelength of monochromatic light is found to be \(x × 10^{–10}\) m. The value of \(x\) is _____ .[Given \(hc = 1242\) eV nm]
In a coil of resistance \(8Ω\), the magnetic flux due to an external magnetic field varies with time as \(Φ=\frac{2}{3}(9−t^2)\).The value of total heat produced in the coil, till the flux becomes zero, will be _ \(J\).
A potentiometer wire of length 300 cm is connected in series with a resistance 780 Ω and a standard cell of emf 4V. A constant current flows through potentiometer wire. The length of the null point for cell of emf20 mV is found to be 60 cm. The resistance of the potentiometer wire is _____ Ω.
A potentiometer wire of length 300 cm is connected in series with a resistance 780 Ω and a standard cell of emf 4V
A source of potential difference \(V\) is connected to the combination of two identical capacitors as shown in the figure. When key \(‘K’\) is closed, the total energy stored across the combination is \(E_1\). Now key \(‘K’\) is opened and dielectric of dielectric constant \(5\) is introduced between the plates of the capacitors. The total energy stored across the combination is now \(E_2\). The ratio \(\frac{E_1}{E_2}\) will be
A source of potential difference V is connected to the combination of two identical capacitors
Two concentric circular loops of radii \(r_1 = 30\) cm and \(r_2 = 50\) cm are placed in \(X–Y\) plane as shown in the figure. \(A\) current \(I = 7 \;A\) is flowing through them in the direction as shown in figure. The net magnetic moment of this system of two circular loops is approximately
Two concentric circular loops
A parallel beam of light is allowed to fall on a transparent spherical globe of diameter 30 cm and refractive index 1.5. The distance from the centre of the globe at which the beam of light can converge is________ mm.
If \(\overrightarrow A=(2\hat i+3\hat j−\hat k)m\) and \(\overrightarrow B=(\hat i+2\hat j+2\hat k)m\). The magnitude of component of vector \(\overrightarrow A\) along vector \(\overrightarrow B\) will be ______\(m\).
The radius of gyration of a cylindrical rod about an axis of rotation perpendicular to its length and passing through the center will be_________m. Given the length of the rod is \(10\sqrt3\; m\).
A car covers AB distance with first one-third at velocity v1 ms–1, second one-third at v2 ms–1 and last one-third at v3 ms–1. If v3 = 3v1, v2 = 2v1 and v1 = 11 ms–1  ,then the average velocity of the car is ____ ms–1.
A car covers AB distance with first