NEET 2019 Physics Paper

The variation of EMF with time for four types of generators are shown in the figures. Which amongst them can be called AC?

A circuit when connected to an AC source of 12 V gives a current of 0.2 A. The same circuit when connected to a DC source of 12 V, gives a current of 0.4 A. The circuit is

The radius of the first permitted Bohr orbit, for the electron, in a hydrogen atom equals 0.51 Å and its ground state energy equals $-13.6\text{ eV}$. If the electron in the hydrogen atom is replaced by muon ($\mu^-$) [charge same as electron and mass $207\, m_e$], the first Bohr radius and ground state energy will be,

The total energy of an electron in an atom in an orbit is –3.4 eV. Its kinetic and potential energies are, respectively.

A parallel plate capacitor of capacitance 20 $\mu$F is being charged by a voltage source whose potential is changing at the rate of 3V/s. The conduction current through the connecting wires, and the displacement current through the plates of the capacitor, would be, respectively:

Two identical capacitors $C_1$ and $C_2$ of equal capacitance are connected as shown in the circuit. Terminals a and b of the key k are connected to charge capacitor $C_1$ using battery of emf V volt. Now disconnecting a and b the terminals b and c are connected. Due to this, what will be the percentage loss of energy?

Which of the following acts as a circuit protection device?

Six similar bulbs are connected as shown in the figure with a DC source of emf E, and zero internal resistance.

The ratio of power consumption by the bulbs when (i) all are glowing and (ii) in the situation when two from section A and one from section B are glowing, will be:

The reading of an ideal voltmeter in the circuit shown is,

In the circuits shown below, the readings of voltmeters and the ammeters will be:

The metre bridge shown is in balance position with $\frac{P}{Q} = \frac{l_1}{l_2}$. If we now interchange the positions of galvanometer and cell, will the bridge work? If yes, what will be balance condition?

An electron is accelerated through a potential difference of 10,000 V. Its de Broglie wavelength is (nearly): (me = 9 $\times$ 10–31 kg)

A proton and an $\alpha$-particle are accelerated from rest to the same energy. The de Broglie wavelengths $\lambda_p$ and $\lambda_\alpha$ are in the ratio,

The work function of a photosensitive material is $4.0\text{ eV}$. The longest wavelength of light that can cause photon emission from the substance is (approximately)

In which of the following devices, the eddy current effect is not used?

A 800 turn coil of effective area 0.05 m2 is kept perpendicular to a magnetic field 5 × 10–5 T. When the plane of the coil is rotated by 90° around any of its coplanar axis in 0.1 s, the emf induced in the coil will be:

A cycle wheel of radius 0.5 m is rotated with constant angular velocity of 10 rad/s in a region of magnetic field of 0.1 T which is perpendicular to the plane of the wheel. The EMF generated between its centre and the rim is,

Which colour of the light has the longest wavelength?

For a transparent medium, relative permeability and permittivity, $\mu_r$ and $\varepsilon_r$ are 1.0 and 1.44 respectively. The velocity of light in this medium would be,

Two point charges A and B, having charges +Q and – Q respectively, are placed at certain distance apart and force acting between them is F. If 25% charge of A is transferred to B, then force between the charges becomes:

A sphere encloses an electric dipole with charges $\pm 3 \times 10^{-6}\text{ C}$. What is the total electric flux across the sphere?

A hollow metal sphere of radius R is uniformly charged. The electric field due to the sphere at a distance r from the centre:

Two parallel infinite line charges with linear charge densities +$\lambda$ C/m and -$\lambda$ C/m are placed at a distance of 2R in free space. What is the electric field mid-way between the two line charges?

Two metal spheres, one of radius $R$ and the other of radius $2R$ respectively have the same surface charge density $\sigma$. They are brought in contact and separated. What will be the new surface charge densities on them?

A small hole of area of cross-section 2 mm2 present near the bottom of a fully filled open tank of height 2 m. Taking g = 10 m/s2, the rate of flow of water through the open hole would be nearly:

In a u-tube as shown in the fig. water and oil are in the left side and right side of the tube respectively. The heights from the bottom for water and oil columns are 15 cm and 20 cm respectively. The density of the oil is

[take $\rho_{\text{water}} = 1000\text{ kg/m}^{3}$]

A body weighs 200 N on the surface of earth. How much will it weigh half way down to the centre of the earth?

A mass falls from a height '$h$' and its time of fall '$t$' is recorded in terms of time period $T$ of a simple pendulum. On the surface of earth it is found that $t = 2T$. The entire set up is taken on the surface of another planet whose mass is half of that of earth and radius the same. Same experiment is repeated and corresponding times noted as $t'$ and $T'$.

Then we can say

The work done to raise a mass m from the surface of the earth to a height h, which is equal to the radius of the earth, is:

Assuming that the gravitational potential energy of an object at infinity is zero, the change in potential energy (final $-$ initial) of an object of mass $m$, when taken to a height $h$ from the surface of earth (of radius $R$), is given by,

The time period of a geostationary satellite is 24 h, at a height $6R_E$ ($R_E$ is radius of earth) from surface of earth. The time period of another satellite whose height is $2.5\,R_E$ from surface will be,

A deep rectangular pond of surface area $A$, containing water (density = $\rho$), specific heat capacity = $s$), is located in a region where the outside air temperature is at a steady value of $-26^\circ\text{C}$. The thickness of the frozen ice layer in this pond, at a certain instant is $x$.

Taking the thermal conductivity of ice as $K$, and its specific latent heat of fusion as $L$, the rate of increase of the thickness of ice layer, at this instant, would be given by

Increase in tempertaure of a gas filled in a container would lead to:

A mass m is attached to a thin wire and whirled in a vertical circle. The wire is most likely to break when:

A truck is stationary and has a bob suspended by a light string, in a frame attached to the truck. The truck suddenly moves to the right with an acceleration of $a$. The pendulum will tilt

A body of mass $m$ is kept on a rough horizontal surface (coefficient of friction = $\mu$). A horizontal force is applied on the body, but it does not move. The resultant of normal reaction and the frictional force acting on the object is given by $F$, where $F$ is,

A block of mass 10 kg is in contact against the inner wall of a hollow cylindrical drum of radius 1 m. The coefficient of friction between the block and the inner wall of the cylinder is 0.1. The minimum angular velocity needed for the cylinder to keep the block stationary when the cylinder is vertical and rotating about its axis, will be: (g = 10 m/s2)

The relations amongst the three elements of earth's magnetic field, namely horizontal component $H$, vertical component $V$ and dip $\delta$ are, ($B_E$ = total magnetic field)

At a point A on the earth’s surface the angle of dip, $\delta$ = + 25°. At a point B on the earth's surface the angle of dip, $\delta$ = – 25°. We can interpret that:

The stress-strain curves are drawn for two different materials X and Y. It is observed that the ultimate strength point and the fracture point are close to each other for material X but are far apart for material Y.

We can say that materials X and Y are likely to be (respectively),

When a block of mass M is suspended by a long wire of length L, the length of the wire becomes (L + $l$). The elastic potential energy stored in the extended wire is:

A person travelling in a straight line moves with a constant velocity $v_1$ for certain distance '$x$' and with a constant velocity $v_2$ for next equal distance. The average velocity $v$ is given by the relation

A person standing on the floor of an elevator drops a coin. The coin reaches the floor in time $t_1$ if the elevator is at rest and in time $t_2$ if the elevator is moving uniformly. Then

A cylindrical conductor of radius R is carrying a constant current. The plot of the magnitude of the magnetic field B with the distance d from the centre of the conductor, is correctly represented by the figure:

Two toroids 1 and 2 have total no. of turns 200 and 100 respectively with average radii 40 cm and 20 cm respectively. If they carry same current $i$, the ratio of the magnetic fields along the two loops is,

A straight conductor carrying current $i$ splits into two parts as shown in the figure. The radius of the circular loop is $R$. The total magnetic field at the centre P of the loop is,

Ionized hydrogen atoms and $\alpha$-particles with same momenta enters perpendicular to a constant magnetic field, B. The ratio of their radii of their paths rH: r$\alpha$ will be:

The rate of radioactive disintegration at an instant for a radioactive sample of half life $2.2 \times 10^{9}\text{ s}$ is $10^{10}\text{ s}^{-1}$. The number of radioactive atoms in that sample at that instant is,

$\alpha$-particle consists of:

The radius of circle, the period of revolution, initial position and sense of revolution are indicated is the figure.

y- projection of the radius vector of rotating particle P is:

The distance covered by a particle undergoing SHM in one time period is (amplitude = $A$),

Average velocity of a particle executing SHM in one complete vibration is:

The displacement of a particle executing simple harmonic motion is given by

y = A0 + A sin$\omega$t + B cos$\omega$t.

Then the amplitude of its oscillation is given by:

Two bullets are fired horizontally and simultaneously towards each other from roof tops of two buildings 100 m apart and of same height of 200 m, with the same velocity of 25 m/s. When and where will the two bullets collide? ($g = 10\text{ m/s}^{2}$)

The speed of a swimmer in still water is 20 m/s. The speed of river water is 10 m/s and is flowing due east. If he is standing on the south bank and wishes to cross the river along the shortest path, the angle at which he should make his strokes w.r.t. north is given by:

An equiconvex lens has power $P$. It is cut into two symmetrical halves by a plane containing the principal axis. The power of one part will be,

Two similar thin equi-convex lenses, of focal length f each, are kept coaxially in contact with each other such that the focal length of the combination is F1. When the space between the two lenses is filled with glycerin (which has the same refractive index ($\mu$ = 1.5) as that of glass) then the equivalent focal length is F2. The ratio F1: F2 will be:

Pick the wrong answer in the context with rainbow.

A double convex lens has focal length 25 cm. The radius of curvature of one of the surfaces is double of the other. Find the radii if the refractive index of the material of the lens is 1.5.

In total internal reflection when the angle of incidence is equal to the critical angle for the pair of media in contact, what will be angle of refraction?

A disc of radius 2 m and mass 100 kg rolls on a horizontal floor. Its centre of mass has speed of 20 cm/s. How much work is needed to stop it?

A solid cylinder of mass 2 kg and radius 50 cm rolls up an inclined plane of angle of inclination $30^\circ$. The centre of mass of the cylinder has speed of 4 m/s. The distance travelled by the cylinder on the inclined surface will be, [take $g = 10\text{ m/s}^{2}$]

Two particles A and B are moving in uniform circular motion in concentric circles of radii rA and rB with speed vA and vB respecitively. Their time period of rotation is the same. The ratio of angular speed of A to that of B will be:

A solid cylinder of mass 2 kg and radius 4 cm is rotating about its axis at the rate of 3 rpm. The torque required to stop after 2$\pi$ revolutions is:

For a p-type semiconductor, which of the following statements is true?

The circuit diagram shown here corresponds to the logic gate,

The correct Boolean operation represented by the circuit diagram drawn is:

An LED is constructed from a p-n junction diode using GaAsP. The energy gap is $1.9\text{ eV}$. The wavelength of the light emitted will be equal to

A soap bubble, having radius of 1 mm, is blown from a detergent having a surface tension of 2.5 $\times$ 10–2 N/m. The pressure inside the bubble equals the pressure at a point Z0 below the free surface of water in a container. Taking g = 10 m/s2, density of water = 103 kg/m3, the value of Z0 is:

1 g of water, of volume $1\text{ cm}^{3}$ at $100^\circ\text{C}$, is converted into steam at same temperature under normal atmospheric pressure ($\simeq 1 \times 10^{5}\text{ Pa}$). The volume of steam formed equals $1671\text{ cm}^{3}$. If the specific latent heat of vaporisation of water is $2256\text{ J/g}$, the change in internal energy is,

The value of $\gamma \left(= \frac{C_p}{C_v}\right)$, for hydrogen, helium and another ideal diatomic gas X (whose molecules are not rigid but have an additional vibrational mode), are respectively equal to,

In which of the following processes, heat is neither absorbed nor released by a system?

A copper rod of 88 cm and an aluminium rod of unknown length have their increase in length independent of increase in temperature. The length of aluminium rod is: ($\alpha$Cu = 1.7 × 10–5 K–1 and $\alpha$Al = 2.2 × 10–5 K–1)

In an experiment, the percentage of error occurred in the measurement of physical quantities A, B, C and D are 1%, 2 %, 3 % and 4 % respectively. Then the maximum percentage of error in the measurement X, where

X = $\frac{A^{2} B^{1/2}}{C^{1/3} D^{3}}$, will be:

The main scale of a vernier callipers has $n$ divisions/cm. $n$ divisions of the vernier scale coincide with $(n - 1)$ divisions of main scale. The least count of the vernier callipers is,

Two small spherical metal balls, having equal masses, are made from materials of densities $\rho_1$ and $\rho_2$ ($\rho_1 = 8\rho_2$) and have radii of 1 mm and 2 mm, respectively. They are made to fall vertically (from rest) in a viscous medium whose coefficient of viscosity equals $\eta$ and whose density is $0.1\rho_2$. The ratio of their terminal velocities would be,

A tuning fork with frequency 800 Hz produces resonance in a resonance column tube with upper end open and lower end closed by water surface. Successive resonance are observed at lengths 9.75 cm, 31.25 cm and 52.75 cm. The speed of sound in air is,

Angular width of the central maxima in the Fraunhofer diffraction for $\lambda = 6000$ Å is $\theta_0$. When the same slit is illuminated by another monochromatic light, the angular width decreases by 30%. The wavelength of this light is

In a double slit experiment, when light of wavelength 400 nm was used, the angular width of the first minima formed on a screen placed 1m away, was found to be 0.2°. What will be the angular width of the first minima, ($\mu$water = 4/3) if the entire experimental apparatus is immersed in water?

In a Young's double slit experiment, if there is no initial phase difference between the light from the two slits, a point on the screen corresponding to the fifth minimum has path difference

A force F = 20 + 10y acts on a particle in y-direction where F is in newton and y in meter. Work done by this force to move the particle from y = 0 to y = 1 m is:

An object of mass 500 g, initially at rest, is acted upon by a variable force whose X-component varies with X in the manner shown. The velocities of the object at the points X = 8 m and X = 12 m, would have the respective values of (nearly)