NTA JEE Main 16th March 2021 Shift 2

A charge $$Q$$ is moving $$d\vec{l}$$ distance in the magnetic field $$\vec{B}$$. Find the value of work done by $$\vec{B}$$.

The magnetic field in a region is given by $$\vec{B} = B_0\left(\frac{x}{a}\right)\hat{k}$$. A square loop of side $$d$$ is placed with its edges along the $$x$$ and $$y$$ axes. The loop is moved with a constant velocity $$\vec{v} = v_0\hat{i}$$. The emf induced in the loop is:

For the given circuit, comment on the type of transformer used:

Red light differs from blue light as they have:

The refractive index of a converging lens is 1.4. What will be the focal length of this lens if it is placed in a medium of same refractive index? (Assume the radii of curvature of the faces of lens are $$R_1$$ and $$R_2$$ respectively)

The de-Broglie wavelength associated with an electron and a proton were calculated by accelerating them through same potential of 100 V. What should nearly be the ratio of their wavelengths? ($$m_p = 1.00727$$ u, $$m_e = 0.00055$$ u)

The half-life of $$Au^{198}$$ is 2.7 days. The activity of 1.50 mg of $$Au^{198}$$, if its atomic weight is 198 g mol$$^{-1}$$ is, ($$N_A = 6 \times 10^{23}$$ mol$$^{-1}$$)

Calculate the time interval between 33% decay and 67% decay if half-life of a substance is 20 min.

The following logic gate is equivalent to:

Two identical antennas mounted on identical towers are separated from each other by a distance of 45 km. What should nearly be the minimum height of receiving antenna to receive the signals in line of sight? (Assume radius of earth is 6400 km)