List of top Physics Questions asked in JEE Main

An amplitude modulated wave is represented by the expression $v _{ m }=5(1+0.6 \cos 6280 t )$ $\sin \left(211 \times 10^{4} t \right)$ volts. The minimum and maximum amplitudes of the amplitude modulated wave are, respectively :

Consider two solid spheres of radii $R, = 1m, \,R_2 = 2m$ and masses $M_1$ and $M_2$, respectively. The gravitational field due to sphere (1) and (2) are shown. The value of $\frac{m_{1}}{m_{2}}$ is :

A bead of mass \(m\) stays at point \(P(a, b)\) on a wire bent in the shape of a parabola \(y=4 c x^{2}\) and rotating with angular speed \(\omega\) (see figure).

The value of \(\omega\) is (neglect friction) :

A rod of length $L$ has non-uniform linear mass density given by $\rho\left(x\right)=a+b\left(\frac{x}{L}\right)^{2},$ where a and b are constants and $0 \le x \le L.$ The value of $x$ for the centre of mass of the rod is a t :

A particle is moving unidirectionally on a horizontal plane under the action of a constant power supplying energy source. The displacement (s) - time (t) graph that describes the motion of the particle is (graphs are drawn schematically and are not to scale) :

Two identical capacitors $A$ and $B$, charged to the same potential $5V$ are connected in two different circuits as shown below at time $t = 0$. If the charge on capacitors $A$ and $B$ at time $t = CR$ is $Q_A$ and $Q_B$ respectively, then (Here e is the base of natural logarithm)

Identify the correct output signal $Y$ in the given combination of gates (as shown) for the given inputs $A$ and $B$.

Water flows in a horizontal tube (see figure). The pressure of water changes by $700\, Nm^{-2}$ between $A$ and $B$ where the area of cross section are $40\, cm^2$ and $20\, cm^2$, respectively. Find the rate of flow of water through the tube. (density of water = $1000\, kgm^{-3}$)

For the circuit shown below, the current through the Zener diode is :

Calculate the limit of resolution of a telescope objective having a diameter of $200\, cm$, if it has to detect light of wavelength $500\, nm$ coming from a star :

Diameter of the objective lens of a telescope is $250\, cm$. For light of wavelength $600\,nm$. coming from a distant object, the limit of resolution of the telescope is close to :

Ice at $-20^{\circ} C$ os added tp $50\, g$ of water at $40^{\circ}C$. When the temperature of the mixture reaches $0^{\circ}C$, it is found that $20\, g$ of ice is still unmelted. The amount of ice added to the water was close to (Specific heat of water = $4.2 \; J/g/^{\circ}C$) Specific heat of Ice = $2.1 \; J/g/^{\circ}C$ Heat of fusion of water at $0^{\circ}C = 334 \; J/g$)

The correct figure that shows, schematically, the wave pattern produced by superposition of two waves of frequencies $9 \,Hz$ and $11\, Hz$ is :

A piece of wood of mass $0.03\, kg$ is dropped from the top of a $100 \,m$ height building. At the same time, a bullet of mass $0.02\, kg$ is fired vertically upward, with a velocity $100 \; ms^{-1}$, from the ground. The bullet gets embedded in the wood. Then the maximum height to which the combined system reaches above the top of the building before falling below is : $(g =10\,ms^{-2})$

A spring whose unstretched length is $l$ has a force constant $k$. The spring is cut into two pieces of unstretched lengths $l_1$ and $l_2$ where, $l_1$ = $nl_2$ and $n$ is an integer. The ratio $k_1/k_2$ of the corresponding force constants, $k_1$ and $k_2$ will be :

A uniform cable of mass $'M'$ and length $'L'$ is placed on a horizontal surface such that its $\bigg(\frac{1}{n}\bigg)^{th}$ part is hanging below the edge of the surface. To lift the hanging part of the cable upto the surface, the work done should be :

An alpha-particle of mass m suffers 1-dimensional elastic coolision with a nucleus at rest of unknown mass. It is scattered directly backwards losing, $64\%$ of its initial kinetic energy. The mass of the nucleus is :

A straight rod of length $L$ extends from $x = a$ to $x = L + a$. The gravitational force is exerts on a point mass $'m'$ at $x = 0$, if the mass per unit length of the rod is $A + Bx^2$, is given by:

Four identical particles of mass $M$ are located at the corners of a square of side $'a'$. What should be their speed if each of them revolves under the influence of other?s gravitational field in a circular orbit circumscribing the square?

If the angular momentum of a planet of mass $m$, moving around the Sun in a circular orbit is $L$, about the center of the Sun, its areal velocity is :

A particle undergoing simple harmonic motion has time dependent displacement given by $x(t) = A \sin \frac{\pi t}{90}$. The ratio of kinetic to potential energy of this particle at $t\, =\, 210\, s$ will be :

A rod of mass $'M'$ and length $'2L'$ is suspended at its middle by a wire. It exhibits torsional oscillations; If two masses each of $'m'$ are attached at distance $'L/2'$ from its centre on both sides, it reduces the oscillation frequency by $20\%$. The value of ratio $m/M$ is close to :

A simple pendulum, made of a string of length $l$ and a bob of mass m, is released from a small angle $\theta_0$. It strikes a block of mass $M$, kept on a horizontal surface at its lowest point of oscillations, elastically. It bounces back and goes up to an angle $\theta_1$. Then M is given by :

A simple pendulum of length $1\, m$ is oscillating with an angular frequency $10\, rad/s$. The support of the pendulum starts oscillating up and down with a small angular frequency of $1 \,rad/s$ and an amplitude of $10^{-2} \; m$. The relative change in the angular frequency of the pendulum is best given by :

A proton and an $\alpha$-particle (with their masses in the ratio of $1 : 4$ and charges in the ratio of $1 : 2$) are accelerated from rest through a potential difference $V$. If a uniform magnetic field (B) is set up perpendicular to their velocities, the ratio of the radii $r_p : r_\alpha$ of the circular paths described by them will be :