JEE Main 2019 Physics Paper: 11 Jan, Shift 1

In the circuit shown,

the switch S1 is closed at time t = 0 and the switch S2 is kept open. At some later time(t0), the switch S1 is opened and S2 is closed. The behavior of the current I as a function of time 't' is given by:

${}$ A hydrogen atom, initially in the ground state is excited by absorbing a photon of wavelength 980$\text{Å}$. The radius of the atom in the excited state, in terms of Bohr radius a0 will be: (hc = 12500 eV$\text{Å}$)

In the figure shown below, the charge on the left plate of the 10$\mu$F capacitor is –30$\mu$C. The charge on the right plate of the 6 $\mu$F capacitor is:

A particle is moving along a circular path with a constant speed of 10 ms–1. What is the magnitude of the change in velocity of the particle, when it moves through an angle of 60o around the centre of the circle?

A body is projected at t = 0 with a velocity 10 ms–1 at an angle of 60o with the horizontal. The radius of curvature of its trajectory at t = 1s is R. neglecting air resistance and taking acceleration due to gravity g = 10 ms–2, the value of R is:

Two equal resistances when connected in series to a battery, consume electric power of 60 W. If these resistances are now connected in parallel combination to the same battery, the electric power consumed will be:

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 Rh = 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 Rh = 6 $\Omega$. The emf $\varepsilon$2 is:

In a Wheatstone bridge(see fig.), Resistances P and Q are approximately equal. When R = 400 $\Omega$, the bridge is balanced. On interchanging P and Q, the value of R, for balance, is 405 $\Omega$. The value of X is close to:

If the de Broglie wavelength of an electron is equal to 10–3 times the wavelength of a photon of frequency 6 $\times$ 1014 Hz, then the speed of electron is equal to: (Speed of light = 3 $\times$ 108 m/s, Planck's constant = 6.63 $\times$ 10–34 J.s, Mass of electron = 9.1 $\times$ 10–31 kg)

There are two long co-axial solenoids of same length $l$. The inner and outer coils have radii r1 and r2 and number of turns per unit length n1 and n2, respectively. The ratio of mutual inductance to the self - inductance of the inner-coil is:

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

The given graph shows variation (with distance r from centre) of:

Three charges Q, + q and + q are placed at the vertices of a right-angle isosceles triangle as shown below. The net electrostatic energy of the configuration is zero, if the value of Q is:

A liquid of density $\rho$ is coming out of a hose pipe of radius a with horizontal speed $v$ and hits a mesh. 50% of the liquid passes through the mesh unaffected. 25% looses all of its momentum and 25% comes back with the same speed. The resultant pressure on the mesh will be:

A satellite is revolving in a circular orbit at a height h from the earth's surface, such that h < < R where R is the radius of the earth. Assuming that the effect of earth's atmosphere can be neglected the minimum increase in the speed required so that the satellite could escape from the gravitational field of earth is:

In an experiment, electrons are accelerated, from rest, by applying a voltage of 500 V. Calculate the radius of the path if a magnetic field 100 mT is then applied. [Charge of the electron = 1.6 $\times$ 10–19 C Mass of the electron = 9.1 $\times$ 10–31 kg]

A particle undergoing simple harmonic motion has time dependent displacement given by x(t) = Asin $\frac{\pi t}{90}$. The ratio of kinetic to potential energy of this particle at t = 210 s 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 Dm is the angle of minimum deviation?

(A)

(B)

(C)

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:

An equilateral triangle ABC is cut from a thin solid sheet of wood. (see figure) D, E and F are the mid- points of its sides as shown and G is the centre of the triangle. The moment of inertia of the triangle about an axis passing through G and perpendicular to the plane of the triangle is I0. If the smaller triangle DEF is removed from ABC, the moment of inertia of the remaining figure about the same axis is I. Then:

A slab is subjected to two forces $\vec{F_1}$ and $\vec{F_2}$ of same magnitude F as shown in the figure. Force $\vec{F_2}$ is in XY-plane while force $\vec{F_1}$ acts along z = axis at the point $\left(2\vec{i} + 3\vec{j}\right).$. The moment of these forces about point O will be:

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

A gas mixture consists of 3 moles of oxygen and 5 moles of argon at temperature T. considering only translational and rotational modes, the total internal energy of the system is:

A rigid diatomic ideal gas undergoes an adiabatic process at room temperature. The relation between temperature and volume for this process is TVx = constant, then x is:

Ice at –20oC is added to 50 g of water at 40oC. When the temperature of the mixture reaches 0oC, it is found that 20 g of ice is still unmelted. The amount of ice added to the water was close to (Specific heat of water = 4.2J/g/oC Specific heat of Ice = 2.1J/g/oC Heat of fusion of water at 0oC= 334J/g)

The force of interaction between two atoms is given by F = $\alpha\beta$exp $\left(-\frac{x^2}{\alpha kT}\right)$; where x is the distance, k is the Boltzmann constant and T is temperature and $\alpha$ and $\beta$ are two constants. The dimension of $\beta$ is:

Equation of travelling wave on a stretched string of linear density 5 g/m is y = 0.03 sin(450 t – 9x) where distance and time are measured in SI units. The tension in the string is:

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