List of top Physics Questions asked in JEE Main

Three point charges of magnitude $5$ $μC$, $0.16μC$ and $0.3μC$ are located at the vertices, $B, C$ of a right angled triangle whose sides are $AB = 3$ cm, $BC = 3\sqrt2$ cm and $CA = 3$ cm and point A is the right angle corner. Charge at point A, experiences ______N of electrostatic force due to the other two charges.

The typical transfer characteristics of a transistor in CE configuration is shown in figure. A load resistor of $2$ $kΩ$ is connected in the collector branch of the circuit used. The input resistance of the transistor is $0.50$ $kΩ$. The voltage gain of the transistor is ________.

In the given figure, the face AC of the equilateral prism is immersed in a liquid of refractive index ‘n‘. For incident angle 60° at the side AC the refracted light beam just grazes along face AC. The refractive index of the liquid n = $(\sqrt x)/4$. The value of $x$ is _______.(Given refractive index of glass = $1.5$)
$the face AC of the equilateral prism is immersed in a liquid of refractive index ‘n‘.$

The area of cross section of the rope used to lift a load by a crane is $2.5 × 10^{–4}$ $m^2$. The maximum lifting capacity of the crane is $10$ metric tons. To increase the lifting capacity of the crane to $25$ metric tons, The required area of cross section of the rope should be

The variation of acceleration due to gravity (g) with distance (r) from the center of the earth is correctly represented by
(Given R = radius of earth)

Mass numbers of two nuclei are in the ratio of $4 : 3$. Their nuclear densities will be in the ratio of

A uniform disc with mass M = 4 kg and radius R = 10 cm is mounted on a fixed horizontal axle as shown in figure.

A block with mass m = 2 kg hangs from a massless cord that is wrapped around the rim of the disc. During the fall of the block, the cord does not slip and there is no friction at the axle. The tension in the cord is _____ N. (Take g = 10 ms^–2)

Two masses $M_1$ and $M_2$ are tied together at the two ends of a light inextensible string that passes over a frictionless pulley. When the mass $M_2$ is twice that of $M_1$, the acceleration of the system is $a_1$. When the mass $M_2$ is thrice that of $M_1$, the acceleration of the system is $a_2$. The ratio $\frac{a_1}{a_2}$ will be

Time period of a simple pendulum in a stationary lift is ‘T’. If the lift accelerates with $\frac{g}{6}$ vertically upwards then the time period will be (Where g = acceleration due to gravity)

A thin circular ring of mass M and radius R is rotating with a constant angular velocity 2 rad s^–1 in a horizontal plane about an axis vertical to its plane and passing through the center of the ring. If two objects each of mass m be attached gently to the opposite ends of a diameter of ring, the ring will then rotate with an angular velocity (in rad s^–1)

Two lighter nuclei combine to from a comparatively heavier nucleus by the relation given below: $^2_1X+^2_1X=^4_2Y$. The binding energies per nucleon for, $^2_1X$ and $^4_2Y$ are 1.1 MeV and 7.6 MeV respectively. The energy released in the process is ______ MeV.

As per given figures, two springs of spring constants k and 2k are connected to mass m. If the period of oscillation in figure (a)is 3s, then the period of oscillation in figure (b) will be $\sqrt x$ s. The value of $x$ is _______

For the network shown below, the value of V_B– V_A is ________V.

A uniform heavy rod of mass $20$ kg, cross sectional area $0.4$ $m^2$ and length $20$ $m$ is hanging from a fixed support. Neglecting the lateral contraction, the elongation in the rod due to its own weight is $x × 10^{–9}$ $m$. The value of $x$ is _____(Given Young’s modulus $Y = 2 × 10^{11} Nm^{–2}$and g = $10\; ms^{–2})$

A thermally insulated vessel contains an ideal gas of molecular mass M and ratio of specific heats 1.4. Vessel is moving with speed ν and is suddenly brought to rest. Assuming no heat is lost to the surrounding and vessel temperature of the gas increases by(R = universal gas constant

A velocity selector consists of electric field $\overrightarrow E=E\hat K$ and magnetic field $\overrightarrow B=B\hat j$ with $B = 12 \;mT$. The value of E required for an electron of energy $728$ $eV$ moving along the positive x-axis to pass undeflected is (Given, mass of electron = $9.1 × 10^{–31}$ kg)

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.

Two capacitors having capacitance C₁ and C₂ respectively are connected as shown in figure. Initially, capacitor C₁ is charged to a potential difference V volt by a battery. The battery is then removed and the charged capacitor C₁ is now connected to uncharged capacitor C₂ by closing the switch S. The amount of charge on the capacitor C₂, after equilibrium, is

Two capacitors having capacitance C1 and C2

Choose the correct statement for amplitude modulation :

The velocity of the bullet becomes one third after it penetrates 4 cm in a wooden block. Assuming that bullet is facing a constant resistance during its motion in the block. The bullet stops completely after travelling at (4 + x) cm inside the block. The value of x is

An electron with speed υ and a photon with speed c have the same de-Broglie wavelength. If the kinetic energy and momentum of electron are E_e and p_e and that of photon are E_ph and p_ph respectively. Which of the following is correct?

The I–V characteristics of a p-n junction diode in forward bias is shown in the figure. The ratio of dynamic resistance, corresponding to forward bias voltage of 2 V and 4 V respectively, is

An expression of energy density is given by
$u = \frac{α}{β} sin (\frac{αx}{kt})$
, where α, β are constants, x is displacement, k is Boltzmann constant and t is the temperature. The dimensions of β will be

In a vernier callipers, each cm on the main scale is divided into 20 equal parts. If tenth vernier scale division coincides with nineth main scale division. Then the value of vernier constant will be____ ×10^–2 mm