NTA JEE Mains 21st Jan 2026 Shift 2

The energy of an electron in an orbit of the Bohr's atom is $$-0.04E_{0} eV$$ where $$E_{0}$$ is the ground state energy. lf L is the angular momentum of the electron in this orbit and h is the Planck's constant, then $$\frac{2\pi L}{h}$$ is __________:

A river of width 200 m is flowing from west to east with a speed of 18 km/h. A boat, moving with speed of 36 km/h in still water, is made to travel one-round trip (bank to bank of the river). Minimum time taken by the boat for this journey and also the displacement along the river bank are _______ and ____________ respectively.

Keeping tl1e significant figures in view, the sum of the physical quantities 52.01 m, 153.2 m and 0.123 m is:

An infinitely long straight wire carrying current I is bent in a planer shape as shown in the diagram. The radius of the circular part is r. The magnetic field at the centre O of the circular loop is :

The r.m.s. speed of oxygen molecules at $$47^\circ$$ is equal to that of the hydrogen molecules kept at ________ $$C^\circ$$. (Mass of oxygen molecule/mass of hydrogen molecule = 32/2)

A body of mass 2 kg is moving along x-direction such that its displacement as function of time is given by x(t) = $$\alpha t^{2} +\beta t +ym$$, where $$\alpha=1m/s^{2}, \beta=1m/s$$ and y=1m. The work done on the body during the time interval t = 2 s to t = 3 s, is _________ J.

As shown in the diagram, when the incident ray is parallel to base of the prism, the emergent ray grazes along the second surface.

If refractive index of the material of prism is $$\sqrt{2}$$, the angle $$\theta$$ of prism is.

A large drum having radius R is spinning around its axis with angular velocity $$\omega$$, as shown in figure. The minimum value of $$\omega$$ so that a body of mass M remains stuck to the inner wall of the drum, taking the coefficient of friction between the drum surface and mass M as $$\mu$$, is :

Surface tension of two liquids (having same densities), $$T_{1}$$ and $$T_{2}$$, are measured using capillary rise method utilizing two tubes with inner radii of $$r_{1}$$ and $$r_{2}$$
where $$r_{1} > r_{2}$$. The measured liquid heights in these tubes are $$h_{1}$$ and $$h_{2}$$ respectively. [Ignore the weight of the liquid about the lowest point of miniscus]. The heights $$h_{1}$$ and $$h_{2}$$ and surfaces tensions $$T_{1}$$ and $$T_{2}$$ satisfy the relation :

The pulley shown in figure is made using a thin rim and two rods of length equal to diameter of the rim. The rim and each rod have a mass of M. Two blocks of mass of M and m are attached to two ends of a light string passing over the pulley, which is hinged to rotate freely in vertical plane about its center. The magnitudes of the acceleration experienced by the blocks is ___________
(assume no slipping of string on pulley).