NEET 2014 Physics

A balloon with mass m is descending down with an acceleration a (where a

A beam of light of λ = 600 nm from a distant source falls on a single slit 1 mm wide and the resulting diffraction pattern is observed on a screen 2 m away. The distance between first dark fringes on either side of the central bright fringe is

A black hole is an object whose gravitational field is so strong that even light cannot escape from it. To what approximate radius would earth (mass= 5.98 × 10²⁴ kg) have to be compressed to be a black hole?

A body of mass (4m) is lying in x-y plane at rest. It suddenly explodes into three pieces. Two pieces, each of mass (m) move perpendicular to each other with equal speeds (v). The total kinetic energy generated due to explosion is:

A certain number of spherical drops of a liquid of radius r coalesce to form a single drop of radius R and volume V. If T is the surface tension of the liquid, then

A conducting sphere of radius R is given a charge Q. The electric potential and the electric field at the centre of the sphere respectively are

A mono-atomic gas at a pressure P, having a volume V expands isothermally to a volume 2V and then adiabatically to a volume 16 V. The final pressure of the gas is (Take γ=5/3)

A particle is moving such that its position coordinates (x,y) are
(2m, 3m) at time t = 0
(6m, 7m) at time t = 2s and
(13m, 14m) at time t = 5s
Average velocity vector from t = 0 to t = 5s is

A potentiometer circuit has been set up for finding the internal resistance of a given cell. The main battery, used across the potentiometer wire, has an emf of 2.0V and a negligible internal resistance. The potentiometer wire itself is 4m long. When the resistance R connected across the given cell, then has values of
(i) infinity (ii) 9.5Ω
The balancing lengths of the potentiometer wire are found to be 3 m and 2.85 m, respectively. The value of internal resistance of the cell is

A projectile is fired from the surface of the earth with a velocity of 5 m s⁻¹ and angle θ with the horizontal. Another projectile fired from another planet with a velocity of 3 m s⁻¹ at the same angle follows a trajectory which is identical with the trajectory of the projectile fired from the earth. The value of the acceleration due to gravity on the planet is (in m s⁻²)is (given g=9.8 m s⁻²)

A radio isotope X with a half life 1.4 x 10⁹ years decays to Y which is stable. A sample of the rock from a cave was found to contain X and Y in the ratio 1:7. The age of the rock is

A solid cylinder of mass 50 kg and radius 0.5 m is free to rotate about the horizontal axis. A mass-less string is wound round the cylinder with one end attached to it and other hanging freely. Tension in the string required to produce an angular acceleration of 2 revolutions s⁻² is

A speeding motorcyclist sees traffic jam ahead him. He slows down to 36 km hour⁻¹. He finds that traffic has eased and a car moving ahead of him at 18 km hour⁻¹ is honking at a frequency of 1392 Hz. If the speed of sound is 343 m s⁻¹, the frequency of the honk as heard by him will be

A system consists of three masses m₁, m₂ and m₃ connected by a string passing over a pulley P. The mass m₁ hangs freely and m₂ and m₃ are on a rough horizontal table (the coefficient of friction = μ). The pulley is frictionless and of negligible mass. The downward acceleration of mass m₁ is (Assume m₁=m₂=m₃=m)

A thermodynamic system undergoes cyclic process ABCDA as shown in figure. The work done by the system in the cycle is

A thin semicircular conducting ring (PQR) of radius r is falling with its plane vertical in a horizontal magnetic field B, as shown in the figure. The potential difference developed across the ring when its speed is v, is

A transformer having efficiency of 90% is working on 200 V and 3kW power supply. If the current in the secondary coil is 6 A, then the voltage across the secondary coil and the current in the primary coil respectively are

Certain quantity of water cools from 70⁰ C to 60⁰C in the first 5 minutes and to 54⁰ C in the next 5 minutes. The temperature of the surroundings is

Copper of fixed volume V is drawn into wire of length l. When this wire is subjected to a constant force F, the extension produced in the wire is Δl. Which of the following graphs is a straight line?

Dependence of intensity of gravitational field (E) of earth with distance(r) from centre of earth is correctly represented by

Following figures show the arrangement of bar magnets in different configurations. Each magnet has magnetic dipole moment m. Which configuration has highest net magnetic dipole moment?

Hydrogen atom in ground state is excited by a monochromatic radiation of λ=975 Å. Number of spectral lines in the resulting spectrum emitted will be

If n₁, n₂ and n₃ are the fundamental frequencies of three segments into which a string is divided, then the original fundamental frequency n of the string is given by

If the focal length of objective lens is increased, then magnifying power of

If the kinetic energy of the particle is increased to 16 times its previous value, the percentage change in the de-broglie wavelength of the particle is

In a region, the potential is represented by V(x,y,z)=6x-8xy-8y+6yz, where V is in volts and x,y,z are in metres. The electric force experienced by a charge of 2 coulomb situated at point (1,1,1) is

In an ammeter, 0.2% of main current passes through the galvanometer. If resistance of galvanometer is G, then the resistance of ammeter will be

In the young’s double slit experiment, the intensity of light at a point on the screen where the path difference λ is K, (λ being the wavelength of light used). The intensity at a point where the path difference is λ/4 will be

The angle of a prism is A. One of its refracting surfaces is silvered. Light rays falling at an angle of incidence 2A on the first surface returns back through the same path after suffering reflection at the silvered surface. The refractive index μ, of the prism is

The barrier potential of a p-n junction depends on
(1) type of semiconductor material
(2) amount of doping
(3) temperature
Which one of the following is correct?

The binding energy per nucleon of ₃⁷Li and ₂⁴He nuclei are 5.60 MeV and 7.06 MeV, respectively. In the nuclear reaction ₃⁷Li+₁¹H→ ₂⁴He+ ₂⁴He+Q, the value of energy Q released is

The force F acting on a particle of mass m is indicated by the force-time graph shown below. The change in momentum of the particle over the time interval from zero to 8 s is

The given graph represents V-I characteristic for a semiconductor device.

Which of the following statement is correct?

The number of possible natural oscillations of air column in a pipe closed at one end of length 85 cm whose frequencies lie below 1250 Hz are (Velocity of sound = 340 m s⁻¹)

The oscillation of a body on a smooth horizontal surface is represented by the equation,
X=A cos(ωt)
where, X=displacement at time t
ω= frequency of oscillation
Which one of the following graphs shows correctly the variation a with t?

The ratio of amplitude of magnetic field to the amplitude of electric field for an electromagnetic wave propagating in vacuum is equal to

The ratio of the accelerations for a solid sphere (mass m and radius R) rolling down an incline of angle θ without slipping and slipping down the incline without rolling is

The resistance in the two arms of the meter bridge are 5Ω and RΩ, respectively. When the resistance R is shunted with an equal resistance, then the new balance point is at 1.6l₁. The resistance R is,

Two identical long conducting wires AOB and COD are placed at right angle to each other, will one above other such that O is their common point for the two. The wires carry I₁ and I₂ currents respectively. Point P is lying at distance d form O along a direction perpendicular to the plane containing the wires. The magnetic field at the point P will be

Two thin dielectric slabs of dielectric constants K₁ and K₂, (K₁ < K₂) are inserted between the plates of a parallel plate capacitor, as shown in the figure alongside. The variation of electric field E between the plates with distance d as measured from plate P is correctly shown by

If force(F), Velocity(V) and time(T) are taken as fundamental units, then the dimensions of mass are

Steam at 100⁰C is passed into 20 g of water at 10°C. When water acquires a temperature of 80°C, the mass of water present will be[Take specific heat of water=1 cal g⁻¹ °C⁻¹ and latent heat of steam=540 cal g⁻¹]

The mean free path of molecules of a gas,(radius ‘r’) is inversely proportional to

Two cities are 150 km apart. Electric power is sent from one city to another city through copper wires. The fall of potential per km is 8 volt and the average resistance per km is 0.5Ω. The power loss in the wires is

Light with an energy flux of 25 x 10⁴ Wm⁻² falls on a perfectly reflecting surface at normal incidence. If the surface area is 15 cm², the average force exerted on the surface is

When the energy of the incident radiation is increased by 20%, the kinetic energy of the photoelectrons emitted from a metal surface increased from 0.5 eV to 0.8 eV. The work function of the metal is