NTA JEE Mains 28th Jan 2025 Shift 2

A uniform magnetic field of 0.4 T acts perpendicular to a circular copper disc 20 cm in radius. The disc is having a uniform angular velocity of $$10\pi rads^{-1}$$ about an axis through its centre and perpendicular to the disc. What is the potential difference developed between the axis of the disc and the rim ? $$(\pi = 3.14)$$

An infinite wire has a circular bend of radius a, and carrying a current I as shown in figure. The magnitude of magnetic field at the origin O of the arc is given by :

In a long glass tube, mixture of two liquids A and B with refractive indices 1.3 and 1.4 respectively, forms a convex refractive meniscus towards . If an object placed at 13 cm from the vertex of the meniscus in A forms an image with a magnification of '-2' then the radius of curvature of meniscus is :

A 400 g solid cube having an edge of length 10 cm floats in water. How much volume of the cube is outside the water ? (Given : density of water $$= 1000 kg m^{-3}$$)

Given below are two statements. One is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : Knowing initial position $$x_{\circ}$$ and initial momentum $$p_{\circ}$$ is enough to determine the position and momentum at any time $$t$$ for a simple harmonic motion with a given angular frequency $$\omega$$. Reason (R): The amplitude and phase can be expressed in terms of $$x_{\circ}$$ and $$p_{\circ}$$. In the light of the above statements, choose the correct answer from the options given below :

A uniform rod of mass 250 g having length 100 cm is balanced on a sharp edge at 40 cm mark. A mass of 400 g is suspended at 10 cm mark. To maintain the balance of the rod, the mass to be suspended at 90 cm mark, is

Earth has mass 8 times and radius 2 times that of a planet. If the escape velocity from the earth is 11.2 km/s. the escape velocity in km/s from the planet will be :

The magnetic field of an E.M. wave is given by $$\vec{B} = \left(\frac{\sqrt{3}}{2}\,\hat{i} + \frac{1}{2}\,\hat{j}\right) 30 \sin\left[\omega \left(t - \frac{z}{c}\right)\right] \; \text{(S.I. Units)}.$$ corresponding electric field in S.I. units is :

The kinetic energy of translation of the molecules in 50 g of $$CO_{2}$$ gas at $$17^{\circ}C$$ is

Which of the following phenomena can not be explained by wave theory of light?