NTA JEE Main 11th January 2019 Shift 1

In the circuit shown, the switch $$S_1$$ is closed at time $$t = 0$$ and the switch $$S_2$$ is kept open. At some later time $$(t_0)$$, the switch $$S_1$$ is opened and $$S_2$$ is closed. The behaviour of the current I as a function of time t is given by:

An electromagnetic wave of intensity $$50 \text{ Wm}^{-2}$$ enters in a medium of refractive index 'n' without any loss. The ratio of the magnitudes of electric fields, and the ratio of the magnitudes of magnetic fields of the wave before and after entering into the medium are respectively, given by:

An object is at a distance of 20 m from a convex lens of focal length 0.3 m. The lens forms an image of the object. If the object moves away from the lens at a speed of 5 m/s the speed and direction of the image will be

The variation of refractive index of a crown glass thin prism with wavelength of the incident light is shown. Which of the following graphs is the correct one, if $$D_m$$ is the angle of minimum deviation?

In a Young's double slit experiment, the path difference, at a certain point on the screen, between two interfering waves is $$\dfrac{1}{8}$$ th of wavelength. The ratio of the intensity at this point to that at the centre of a bright fringe is close to:

If the deBroglie wavelength of an electron is equal to $$10^{-3}$$ times the wavelength of a photon of frequency $$6 \times 10^{14}$$ Hz, then the speed of electron is equal to: (Speed of light $$= 3 \times 10^8$$ m/s, Planck's constant $$= 6.63 \times 10^{-34}$$ J.s, Mass of electron $$= 9.1 \times 10^{-31}$$ kg)

A hydrogen atom, initially in the ground state is excited by absorbing a photon of wavelength 980 $$\widetilde{A}$$. The radius of the atom in the excited state, in terms of Bohr radius $$a_0$$, will be:

In the given circuit the current through Zener Diode is close to:

An amplitude modulated signal is given by $$V(t) = 10[1 + 0.3 \cos(2.2 \times 10^4 t)] \sin(5.5 \times 10^5 t)$$. Here t is in seconds. The sideband frequencies (in kHz) are, [Given $$\pi = 22/7$$]

The resistance of the meter bridge AB in given figure is $$4\Omega$$. With a cell of emf $$\varepsilon = 0.5$$ V and rheostat resistance $$R_h = 2\Omega$$ the null point is obtained at some point J. When the cell is replaced by another one of emf $$\varepsilon = \varepsilon_2$$ the same null point J is found for $$R_h = 6\Omega$$. The emf $$\varepsilon_2$$ is: