JEE Main Physics Questionbank

The dimensional formula of pressure is:

A ball is thrown vertically upward with velocity $20\ \mathrm{m/s}$. Taking $g = 10\ \mathrm{m/s^2}$, the total time to return to the thrower's hand is:

A block of mass 5 kg rests on a rough horizontal surface ($\mu = 0.4$). The minimum horizontal force (in N) needed to start moving the block is ______. (Take $g = 10\ \mathrm{m/s^2}$)

A body of mass 2 kg moving at 6 m/s collides head-on and perfectly inelastically with a stationary body of mass 4 kg. The kinetic energy lost in the collision is:

A solid sphere rolls without slipping down an incline. The fraction of its total kinetic energy that is rotational is:

The escape velocity from a planet is $v$. If the planet's mass were doubled keeping radius the same, the new escape velocity would be $x\,v$. Find $x$. (Round to 2 decimals.)

An ideal gas undergoes an isothermal expansion at temperature $T$, doing work $W$ on the surroundings. The heat absorbed by the gas is:

A simple pendulum has time period $T$ on Earth's surface. On a planet where $g$ is four times larger, its period becomes:

Two point charges $+q$ and $-q$ are separated by distance $d$. The electric potential at the midpoint of the line joining them is:

A wire of resistance $12\ \Omega$ is cut into three equal parts and the parts are connected in parallel. The equivalent resistance (in $\Omega$) is ______. (Round to 2 decimals.)

A charged particle enters a uniform magnetic field perpendicular to its velocity. Which quantity stays constant during the motion?

In an ideal transformer, the primary has 100 turns and the secondary 500 turns. If the primary voltage is 20 V, the secondary voltage is:

An object is placed at twice the focal length from a thin convex lens. The image formed is:

If the momentum of a particle is doubled, its de Broglie wavelength becomes:

In a hydrogen atom the electron jumps from $n=3$ to $n=2$. The emitted photon energy in eV is closest to ______. (Round to 1 decimal; ground-state energy $=-13.6$ eV)

In a forward-biased p-n junction diode, the depletion layer width:

Water rises to height $h$ in a capillary tube. If the tube's radius is halved, the rise becomes:

The rms speed of gas molecules at 300 K is $v$. At 1200 K (same gas), the rms speed becomes $x\,v$. Find $x$ rounded to the nearest integer.

Assertion: In an elastic collision between two identical masses where one is initially at rest, they exchange velocities.

Reason: Both kinetic energy and linear momentum are conserved in an elastic collision.

Which region of the electromagnetic spectrum carries the most energetic photons?

A flywheel rotating at 60 rpm is brought to rest with constant angular deceleration in 10 s. The number of revolutions it completes while stopping is ______. (Round to nearest integer.)

In Young's double-slit experiment, the slit separation is doubled while the screen distance is halved. The fringe width: