List of top Physics Questions asked in JEE Main

An object O is placed at a distance of 100 cm in front of a concave mirror of radius of curvature 200 cm as shown in the figure. The object starts moving towards the mirror at a speed 2 cm/s. The position of the image from the mirror after 10 s will be at ____ cm.

An electrical bulb rated 220 V, 100 W, is connected in series with another bulb rated 220 V, 60 W. If the voltage across combination is 220 V, the power consumed by the 100 W bulb will be about ____ W.

For the given circuit the current through battery of 6 V just after closing the switch S will be _____ A.

A balloon has mass of 10 g in air The air escapes from the balloon at a uniform rate with velocity 4.5 cm/s If the balloon shrinks in 5 s completely Then, the average force acting on that balloon will be (in dyne)

In an experiment with a convex lens, the plot of the image distance (ν′) against the object distance (μ′) measured from the focus gives a curve ν′μ′ = 225. If all the distances are measured in cm. The magnitude of the focal length of the lens is _______ cm.

The potential energy of a particle of mass $4 kg$ in motion along the x-axis is given by $U = 4(1- cos 4x) J$. The time period of the particle for small oscillation $(sin θ ≃ θ)$ is $(\frac{π}{K})$ s. The value of $K$ is ..........

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 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

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 $=2 \times 10^{11} N / m ^2$ )

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)

At time t = 0, a material is composed of two radioactive atoms A and B, where N$_A$(0) = 2N$_B$(0). The decay constant of both kind of radioactive atoms is $\lambda$. However, A disintegrates to B and B disintegrates to C. Which of the following figures represents the evolution of N$_B$(t)/N$_B$(0) with respect to time t?
[ $N_A(0)$ = No. of A atoms at t = 0 ]
[ $N_B(0)$ = No. of B atoms at t = 0 ]

There are 10$^{10}$ radioactive nuclei in a given radioactive element. Its half-life time is 1 minute. How many nuclei will remain after 30 seconds ? ($\sqrt{2}$ = 1.414)

The decay of a proton to neutron is:

A parallel-plate capacitor with plate area A has separation d between the plates. Two dielectric slabs of dielectric constant K$_1$ and K$_2$ of same area A/2 and thickness d/2 are inserted in the space between the plates. The capacitance of the capacitor will be given by:

The two thin coaxial rings, each of radius 'a' and having charges +Q and -Q respectively are separated by a distance of 's'. The potential difference between the centres of the two rings is:

A capacitor of $ 50 \, \mu F $ is connected in a circuit as shown in figure. The charge on the upper plate of the capacitor is $\dots\dots\dots$ $ \mu C $.

If the maximum value of accelerating potential provided by a radio frequency oscillator is 12 kV. The number of revolution made by a proton in a cyclotron to achieve one sixth of the speed of light is __________.
[m$_p$ = 1.67$ \times $10$^{-27}$ kg, e = 1.6$ \times $10$^{-19}$ C, Speed of light = 3$ \times $10$^8$ m/s]

A coil in the shape of an equilateral triangle of side 10 cm lies in a vertical plane between the pole pieces of permanent magnet producing a horizontal magnetic field 20 mT. The torque acting on the coil when a current of 0.2 A is passed through it and its plane becomes parallel to the magnetic field will be $ \sqrt{x} \times 10^{-5} $ Nm. The value of x is __________.

The fractional change in the magnetic field intensity at a distance 'r' from centre on the axis of current carrying coil of radius 'a' to the magnetic field intensity at the centre of the same coil is : (Take $r \ll a$)

A proton, a deuteron and an $\alpha$ particle are moving with same momentum in a uniform magnetic field. The ratio of magnetic forces acting on them is __________ and their speed is __________, in the ratio.

A proton and an $\alpha$-particle enter into a magnetic field at right angles. The ratio of the radii of trajectory of proton to that of $\alpha$-particle is 2 : 1. The ratio of $K_p : K_{\alpha}$ is:

A source of light is placed in front of a screen. Intensity of light on the screen is I. Two Polaroids P$_1$ and P$_2$ are so placed in between the source of light and screen that the intensity of light on screen is I/2. P$_2$ should be rotated by an angle of __________ (degrees) so that the intensity of light on the screen becomes $\frac{3I}{8}$.

An object is placed at a distance of 12 cm from a convex lens. A convex mirror of focal length 15 cm is placed on other side of lens at 8 cm as shown in the figure. Image of object coincides with the object. When the convex mirror is removed, a real and inverted image is formed at a position. The distance of the image from the object will be __________ (cm).