AIPMT-PRELIMS Physics Questions

The enthalpy of fusion of water is 1.435 kcal/mol. The molar entropy change for the melting of ice at 0°C

In which of the following reactions, standard reaction entropy change (ΔS°) is positive and standard Gibb’s energy change (ΔG°) decreases sharply with increasing temperature?

Standard enthalpy of vaporisation ΔvapH⁰ for water at 100°C is 40.66 kJmol⁻¹. The internal energy of vaporisation of water at 100°C (in kJ mol⁻¹) is

In a CE transistor amplifier, the audio signal voltage across the collector resistance of 2 kΩ is 2V. If the base resistance is 1 kΩ and the current amplification of the transistor is 100, the input signal voltage is

A coil of resistance 400 Ω is placed in a magnetic field. If the magnetic flux ϕ (wb) linked with the coil varies with time t (sec) as ϕ = 50 t² + 4, the current in the coil at t = 2 sec is

Liquid oxygen at 50 K is heated to 300 K at constant pressure of 1 atm. The rate of heating is constant. Which one of the following graphs represents the variation of temperature with time?

One mole of an ideal gas goes from an initial state A to final state B via two processes: It first undergoes isothermal expansion from volume V to 3V and then its volume is reduced from 3V to V at constant pressure. The correct P⁻V diagram representing the two processes is:

A solid cylinder of mass 3 kg is rolling on a horizontal surface with velocity 4 ms⁻¹. It collides with a horizontal spring of force constant 200 Nm⁻¹. The maximum compression produced in the spring will be

An electric dipole of moment ‘p’ is placed in an electric field of intensity ‘E’. The dipole acquires a position such that the axis of the dipole makes an angle θ with the direction of the field. Assuming that the potential energy of the dipole to be zero when θ = 90°, the torque and the potential energy of the dipole will respectively be

The horizontal range and the maximum height of a projectile are equal. The angle of projection of the projectile is

If the nuclear radius of ²⁷Al is 3.6 Fermi, the approximate nuclear radius of ⁶⁴Cu in Fermi is:

Two similar coils of radius R are lying concentrically with their planes at right angles to each other. The currents flowing in them are I and 2I, respectively. The resultant magnetic field induction at the centre will be

When a biconvex lens of glass having refractive index 1.47 is dipped in a liquid, it acts as a plane sheet of glass. This implies that the liquid must have refractive index

Two ideal diodes are connected to a battery as shown in the circuit. The current supplied by the battery is

Two spheres A and B of masses m₁ and m₂ respectively collide. A is at rest initially and B is moving with velocity v along x-axis. After collision B has a velocity \( \frac{v}{2} \) in a direction perpendicular to the original direction. The mass A moves after collision in the direction

A particle has initial velocity \(-2\hat{i} + 3\hat{j}\) and acceleration \(0.3\hat{i} + 0.2\hat{j}\). The magnitude of velocity after 10 seconds will be

The height which the weight of a body becomes 1/16^{th}, its weight on the surface of earth (radius R) is

Four point charges –Q, –q, 2q and 2Q are placed, one at each corner of the square. The relation between Q and q for which the potential at the centre of the square is zero is

When a string is divided into three segments of length l₁, l₂, and l₃, the fundamental frequencies of these three segments are v₁, v₂ and v₃ respectively. The original fundamental frequency (v) of the string is

A ring is made of a wire having a resistance R₀ = 12 Ω. Find the points A and B, as shown in the figure, at which a current carrying conductor should be connected so that the resistance R of the sub circuit between these points is equal to 8/3 Ω.

A geostationary satellite is orbiting the earth at a height of 5R above the surface of the earth, R being the radius of the earth. The time period of another satellite in hours at a height of 2R from the surface of the earth is

ABC is an equilateral triangle with O as its centre. F̅₁, F̅₂ and F̅₃ represent three forces acting along the sides AB, BC and AC respectively. If the total torque about O is zero then the magnitude of F̅₃ is

If the radius of a star is R and it acts as a black body, what would be the temperature of the star, in which the rate of energy production is Q?

When a mass is rotating in a plane about a fixed point, its angular momentum is directed along:

Two sources of sound placed close to each other, are emitting progressive waves given by y₁ = 4 sin 600 πt and y₂ = 5 sin 608 πt. An observer located near these two sources of sound will hear:

A car of mass 1000 kg negotiates a banked curve of radius 90 m on a frictionless road. If the banking angle is 45°, the speed of the car is

The magnifying power of a telescope is 9. When it is adjusted for parallel rays the distance between the objective and eyepiece is 20 cm. The focal length of lenses are

What is the flux through a cube of side ‘a’ if a point charge of q is at one of its corner?

An α-particle moves in a circular path of radius 0.83 cm in the presence of a magnetic field of 0.25 Wb/m². The de Broglie wavelength associated with the particle will be

The figure shows a logic circuit with two inputs A and B and the output C. The voltage wave forms across A, B and C are as given. The logic circuit gate is

A compass needle which is allowed to move in a horizontal plane is taken to a geomagnetic pole. It:

A spherical planet has a mass Mₚ and diameter Dₚ. A particle of mass m falling freely near the surface of this planet will experience an acceleration due to gravity, equal to

A 200 W sodium street lamp emits yellow light of wavelength 0.6 μm. Assuming it to be 25% efficient in converting electrical energy to light, the number of photons of yellow light it emits per second is

The potential energy of a particle in a force field is: U = A/r² - B/r, where A and B are positive constants and r is the distance of particle from the centre of the field. For stable equilibrium the distance of the particle is

An electron of a stationary hydrogen atom passes from the fifth energy level to the ground level. The velocity that the atom acquired as a result of photon emission will be

In the circuit shown the cells A and B have negligible resistances. For Vₐ = 12V, R₁ = 500 Ω and R = 100 Ω the galvanometer (G) shows no deflection. The value of V_b is

Monochromatic radiation emitted when electron on hydrogen atom jumps from first excited to the ground state irradiates a photosensitive material. The stopping potential is measured to be 3.57 V. The threshold frequency of the material is

A mixture consists of two radioactive materials A₁ and A₂, with half lives of 20 s and 10 s respectively. Initially the mixture has 40 g of A₁ and 160 g of A₂. The amount of the two in the mixture will become equal after

If voltage across a bulb rated 220 Volt^{-100} Watt drops by 2.5% of its rated value, the percentage of the rated value by which the power would decrease is

Transfer characteristics [output voltage(V₀) vs input voltage (Vᵢ)] for a base biased transistor in CE configuration is as shown in the figure. For using transistor as a switch, it is used

C and Si both have same lattice structure, having 4 bonding electrons in each. However, C is insulator whereas Si is intrinsic semiconductor. This is because

Two persons of masses 55 kg and 65 kg respectively, are at the opposite ends of a boat. The length of the boat is 3.0 m and weighs 100 kg. The 55 kg man walks up to the 65 kg man and sits with him. If the boat is in still water the centre of mass of the system shifts by

A thermodynamic system is taken through the cycle ABCD as shown in figure. Heat rejected by the gas during the cycle is

The motion of a particle along a straight line is described by equation: x = 8 + 12t - t³ where x is in metre and t in second. The retardation of the particle when its velocity becomes zero, is

A concave mirror of focal length f₁ is placed at a distance of d from a convex lens of focal length f₂. A beam of light coming from infinity and falling on this convex lens-concave mirror combination returns to infinity. The distance ‘d’ must equal

A milli voltmeter of 25 milli volt range is to be converted into an ammeter of 25 ampere range. The value (in Ω) of necessary shunt will be

The damping force on an oscillator is directly proportional to the velocity. The units of the constant of proportionality are

A ray of light is incident at an angle of incidence, i on one face of a prism of angle A (assumed to be small) and emerges normally from the opposite face. If the refractive index of the prism is μ, the angle of incidence i, is nearly equal to

Electron in hydrogen atom first jumps from third excited state to second excited state and then from second excited to the first excited state. The ratio of the wavelengths λ₁ : λ₂ emitted in the two cases is

The electric field associated with an e.m. wave in vacuum is given by E̅ = î40cos(kz − 6 × 10⁸t), where E, z and t are in volt/m, meter and seconds respectively. The value of wave vector k is