NEET : Physics – 2019 – Exam Mode

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

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

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

The correct Boolean operation represented by the circuit diagram drawn 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 )

Body A of mass 4m moving with speed u collides with another body B of mass 2m, at rest. The collision is head on and elastic in nature. After the collision the fraction of energy lost by the colliding body A is :

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 :

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

The displacement of a particle executing simple harmonic motion is given by y = A₀+ Asinωt + Bcosωt
Then the amplitude of its oscillation is given by :

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:

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

A soap bubble, having radius of 1 mm, is blown from a detergent solution having a surface tension of 2.5 × 10^-2 N/m. The pressure inside the bubble equals 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 :

A copper rod of 88 cm and an aluminum rod of unknown length have their increase in length independent of increase in temperature.

The length of aluminum rod is :

(α_Cu = 1.7 × 10^-5 K^-1 and α_Al = 2.2 × 10^-5 K^-1)

The unit of thermal conductivity is :

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 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?

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 = A²B^1/2/C^1/3 D³ will be

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

Which colour of the light has the longest wavelength?

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 2π revolutions is

The radius of circle, the period of revolution, initial position and sense of revolution are indicated in the fig.

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

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

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

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 :

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

A force F = 20 + 10 y acts on a particle in ydirection 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

Pick the wrong answer in the context with rainbow.

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 particles A and B are moving in uniform circular motion in concentric circles of radii r_A and r_B with speed v_A and v_B respectively. Their time period of rotation is the same. The ratio of angular speed of A to that of B 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 glycerine (which has the same refractive index (μ = 1.5) as that of glass) then the equivalent focal length is F2. The ratio F1 : F2 will be :

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?

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

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

Which of the following acts as a circuit protection device?

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

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

α-particle consists of :

An electron is accelerated through a potential  difference of 10,000 V. Its de Broglie wavelength is, (nearly) : (m_e= 9 × 10^-31 kg)

When an object is shot from the bottom of a long smooth inclined plane kept at an angle 60° with horizontal, it can travel a distance x₁ along the plane. But when the inclination is decreased to 30° and the same object is shot with the same velocity, it can travel x₂ distance.

Then x₂: x₂ will be:

A small hole of area of cross-section 2 mm² is 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

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 :

Ionized hydrogen atoms and α-particles with same momenta enters perpendicular to a constant magnetic field, B.

The ratio of their radii of their paths r_H : r_α will be :

A particle moving with velocity V is acted by three forces shown by the vector triangle PQR.

The velocity of the particle will :

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:

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 1 m away, was found to be 0.2°. What will be the angular width of the first minima, if the entire experimental apparatus is immerse in water? (μ_water= 4/3)