JEE Main 2019 Physics Paper: 10 Apr, Shift 1

A transformer consisting of 300 turns in the primary and 150 turns in the secondary gives output power of 2.2 kW. If the current in the secondary coil is 10A, then the input voltage and current in the primary coil are:

Figure shows charge (q) versus voltage (V) graph for series and parallel combination of two given capacitors. The capacitances are:

In the given circuit, an ideal voltmeter connected across the 10$\Omega$ resistance reads 2V. The internal resistance r, of each cell is:

A current of 5 A passes through a copper conductor (resistivity = 1.7 × 10–8 $\Omega$m) of radius of cross- section 5 mm. Find the mobility of the charges if their drift velocity is 1.1 × 10–3 m/s.

A moving coil galvanometer allows a full scale current of 10–4 A. A series resistance of 2 M$\Omega$ is required to convert the above galvanometer into a voltmeter of range 0-5 V. Therefore the value of shunt resistance required to convert the above galvanometer into an ammeter of range 0-10 mA is:

In an experiment, the resistance of a material is plotted as a function of temperature (in some range). As shown in the figure, it is a straight line. One may conclude that:

In a meter bridge experiment, the circuit diagram and the corresponding observation table are shown in figure

Which of the readings is inconsistent?

In a photoelectric effect experiment the threshold wavelength of the light is 380 nm. If the wavelentgh of incident light is 260 nm, the maximum kinetic energy of emitted electrons will be: Given E (in eV) = 1237/$\lambda$ (in nm)

The electric field of a plane electromagnetic wave is given by

$\vec{E} = E_0 \hat{i} \cos(kz) \cos(\omega t)$

The corresponding magnetic field $\vec{B}$ is then given by

A uniformly charged ring of radius 3a and total charge q is placed in xy-plane centred at origin. A point charge q is moving towards the ring along the z-axis and has speed u at z = 4a. The minimum value of u such that it crosses the origin is:

The value of acceleration due to gravity at Earth's surface is 9.8 ms–2. The altitude above its surface at which the acceleration due to gravity decreases to 4.9 ms–2, is close to: (Radius of earth = 6.4 × 106 m)

A 25 × 10–3 m3 volume cylinder is filled with 1 mol of O2 gas at room temperature (300K). The molecular diameter of O2, and its root mean square speed, are found to be 0.3 nm, and 200 m/s, respectively. What is the average collision rate (per second) for an O2 molecule?

A ball is thrown upward with an initial velocity V0 from the surface of the earth. The motion of the ball is affected by a drag force equal to m$\gamma$u2 (where m is mass of the ball, u is its instantaneous velocity and $\gamma$ is a constant). Time taken by the ball to rise to its zenith is:

Two wires A & B are carrying currents I1 & I2 as shown in the figure. The separation between them is d. A third wire C carrying a current I is to be kept parallel to them at a distance x from A such that the net force acting on it is zero. The possible values of x are:

A proton, an electron, and a Helium nucleus, have the same energy. They are in circular orbits in a plane due to magnetic field perpendicualr to the plane. Let rp, re and rHe be their respective radii, then

Two radioactive materials A and B have decay constants 10$\lambda$ and $\lambda$, respectively. It initially they have the same number of nuclei, then the ratio of the number of nuclei of A to that of B will be 1/e after a time:

The displacement of a damped harmonic oscillator is given by

x(t) = e–0.1t cos (10$\pi$t + f).

Here t is in seconds. The time taken for its amplitude of vibration to drop to half of its initial value is close to:

One plano-convex and one plano-concave lens of same radius of curvature 'R' but of different materials are joined side by side as shown in the figure. If the refractive index of the material of 1 is $\mu$1 and that of 2 is $\mu$2, then the focal length of the combination is:

A ray of light AO in vacuum is incident on a glass slab at angle 60° and refracted at angle 30° along OB as shown in the figure. The optical path length of light ray from A to B is:

Two coaxial discs, having moments of inertia I1 and I1/2, are rotating with respective angular velocities $\omega$1 and $\omega$1/2, about their common axis. They are brought in contact with each other and thereafter they rotate with a common angular velocity. If Ef and Ei are the final and initial total energies, then (Ef - Ei) is:

A thin disc of mass M and radius R has mass per unit area $\sigma$(r) = kr2 where r is the distance from its centre. Its moment of inertia about an axis going through its centre of mass and perpendicular to its plane is:

A particle of mass m is moving along a trajectory given by

x = x0 + a cos$\omega$1t

y = y0 + b sin$\omega$2t

The torque, acting on the particle about the origin, at t = 0 is:

An n-p-n transistor operates as a common emitter amplifier, with a power gain of 60 dB. The input circuit resistance is 100$\Omega$ and the output load resistance is 10 k$\Omega$. The common emitter current gain $\beta$ is:

The ratio of surface tensions of mercury and water is given to be 7.5 while the ratio of their densities is 13.6. Their contact angles, with glass, are close to 135° and 0°, respectively. It is observed that mercury gets depressed by an amount h in a capillary tube of radius r1, while water rises by the same amount h in a capillary tube of radius r2. The ratio, (r1/r2), is then close to:

A cylinder with fixed capacity of 67.2 lit contains helium gas at STP. The amount of heat needed to raise the temperature of the gas by 20°C is: [Given that R = 8.31 J mol–1 K–1]

n moles of an ideal gas with constant volume heat capcity CV undergo an isobaric expansion by certain volume. The ratio of the work done in the process, to the heat supplied is:

A stationary source emits sound waves of frequency 500 Hz. Two observers moving along a line passing through the source detect sound to be of frequencies 480 Hz and 530 Hz. Their respective speeds are, in ms–1, (Given speed of sound = 300 m/s)