JEE Main entrance exam Question Bank Solutions for Physics (JEE Main)

If 13.6 eV energy is required to ionize the hydrogen atom, then the energy required to remove an electron from n = 2 is ______.

A transmitting antenna has a height of 320 m and that of receiving antenna is 2000 m. The maximum distance between them for satisfactory communication in line of sight mode is 'd'. The value of 'd' is ______ km.

A cyclic process ABCA is shown in the V-T diagram. A process on the P-V diagram is ______.

A 100 eV electron collides with a stationary helium ion (He⁺) in its ground state and exits to a higher level. After the collision, He⁺ ions emit two photons in succession with wavelengths 1085 Å and 304 Å. The energy of the electron after the collision will be ______ eV.

Given h = 6.63 × 10^-34 Js.

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).

This question has Statement 1 and Statement 2. Of the four choices given after the Statements, choose the one that best describes the two Statements.

Statement 1: If you push on a cart being pulled by a horse so that it does not move, the cart pushes you back with an equal and opposite force.

Statement 2: The cart does not move because the force described in statement 1 cancel each other.

A cylindrical container of volume 4.0 × 10^-3 m³ contains one mole of hydrogen and two moles of carbon dioxide. Assume the temperature of the mixture is 400 K. The pressure of the mixture of gases is ______.

[Take gas constant as 8.3 J mol^-1 K^-1]

The photocurrent in an experiment on photoelectric effect increases if ______.

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 `a/3 R^2` ω. The value of a will be:

A person whose mass is 100 kg travels from Earth to Mars in a spaceship. Neglect all other objects in the sky and take acceleration due to gravity on the surface of the Earth and Mars as 10 m/s² and 4 m/s² respectively. Identify from the below figures, the curve that fits best for the weight of the passenger as a function of time.

Region I and II are separated by a spherical surface of a radius of 25 cm. An object is kept in the region I at a distance of 40 cm from the surface. The distance of the image from the surface is ______.

An audio signal v_m = 20sin2π(1500t) amplitude modulates a carrier v_c = 80 sin 2π (100,000t). The value of percent modulation is ______.

An amplitude-modulated wave is represented by C_m(t) = 10(1 + 0.2 cos 12560t) × sin (111 × 10⁴t) volts. The modulating frequency in kHz will be ______.

An electric fan has blades of length 30 cm as measured from the axis of rotation. If the fan is rotating at 1200 r.p.m. The acceleration of a point on the tip of the blade is about:

A rod of mass 'm' hinged at one end is free to rotate in a horizontal plane. A small bullet of mass m/4 travelling with speed 'u' hits the rod and attaches to it at its centre. Find the angular speed of rotation of rod just after the bullet hits the rod 3. [take length of the rod as 'l']

If R is the radius of the earth and g is the acceleration due to gravity on the earth's surface, the mean density of the earth is ______.

A spherical surface of radius R separates two medium of refractive indices µ₁ and µ₂, as shown in figure. Where should an object be placed in the medium 1 so that a real image is formed in medium 2 at the same distance?

Consider a gravity-free hall in which an experimenter of mass 50 kg is resting on a 5 kg pillow, 8 ft above the floor of the hall. He pushes the pillow down so that it starts falling at a speed of 8 ft/s. The pillow makes a perfectly elastic collision with the floor, rebounds and reaches the experimenter's head. The time elapsed in the process is ______ s.

Four particles A, B, C, and D with masses m_A = m, m_B = 2m, m_C = 3m, and m_D = 4m are at the corners of a square. They have accelerations of equal magnitude with directions as shown. The acceleration of the centre of mass of the particles is ______.

Radiation coming from transitions n = 2 to n = 1 of hydrogen atoms fall on He⁺ ions in n = 1 and n = 2 states. The possible transition of helium ions as they absorb energy from the radiation is ______.