Previous Years Questions
IIT-JEE/NEET
Physics
1. Out of the following pair, which one does not have identical dimensions is
2. The relation between time t and distance x is t = ax2 + bx where a and b are constants. The acceleration is
3. A car, starting from rest, accelerates at the rate f through a distance S, then continues at constant speed for time t and then decelerates at the rate f2 to come to rest. If the total distance traversed is 15S, then
4. A particle is moving eastwards with a velocity of 5 ms−1. In 10 seconds the velocity changes to 5 ms−1 northwards. The average acceleration in this time is
5. A projectile can have the same range ‘R’ for two angles of projection. If ‘t1’ and ‘t2’ be the times of flights in the two cases, then the product of the two time of flights is proportional to
6. An annular ring with inner and outer radii R1 and R2 is rolling without slipping with a uniform angular speed. The ratio of the forces experienced by the two particles situated on the inner and outer parts of the ring, F1F2 is
7. A smooth block is released at rest on a 45° incline and then slides a distance ‘d’. The time taken to slide is ‘n’ times as much to slide on rough incline than on smooth incline. The coefficient of friction is
8. The upper half of an inclined plane with inclination φ is perfectly smooth while the lower half is rough. A body starting from rest at the top will again come to rest at the bottom if the coefficient of friction for the lower half is given by
9. A bullet fired into a fixed target loses half of its velocity after penetrating 3 cm. How much further will it penetrate before coming to rest assuming that it faces constant resistance to motion?
10. A parachutist after bailing out falls 50 m without friction. When parachute opens, it decelerates at 2 m/s2. He reaches the ground with a speed of 3 m/s. At what height did he bail out?
11. A particle of mass 0.3 kg is subjected to a force F = −kx with k = 15 N/m. What will be its initial acceleration if it is released from a point 20 cm away from the origin?
12. The block of mass M moving on the frictionless horizontal surface collides with the spring of spring constant K and compresses it by length L. The maximum momentum of the block after collision is
13. A mass ‘m’ moves with a velocity ‘v’ and collides inelastically with another identical mass. After collision the 1st mass moves with velocity v√3 in a direction perpendicular to the initial direction of motion. Find the speed of the 2nd mass after collision.
14. A spherical ball of mass 20 kg is stationary at the top of a hill of height 100 m. It rolls down a smooth surface to the ground, then climbs up another hill of height 30 m and finally rolls down to a horizontal base at a height of 20 m above the ground. The velocity attained by the ball is
15. A block is kept on a frictionless inclined surface with angle of inclination ‘α’. The incline is given an acceleration ‘a’ to keep the block stationary. Then a is equal to
16. The moment of inertia of a uniform semicircular disc of mass M and radius r about a line perpendicular to the plane of the disc through the centre is
17. A body A of mass M while falling vertically downwards under gravity breaks into two parts; a body B of mass M / 3 and a body C of mass 2M / 3. The centre of mass of bodies B and C taken together shifts compared to that of body A towards
18. A ‘T’ shaped object with dimensions shown in the figure, is lying on a smooth floor. A force ‘F’ is applied at the point P parallel to AB, such that the object has only the translational motion without rotation. Find the location of P with respect to C
19. The change in the value of ‘g’ at a height ‘h’ above the surface of the earth is the same as at a depth ‘d’ below the surface of earth. When both ‘d’ and ‘h’ are much smaller than the radius of earth, then which one of the following is correct
20. A particle of mass 10 g is kept on the surface of a uniform sphere of mass 100 kg and radius 10 cm. Find the work to be done against the gravitational force between them to take the particle far away from the sphere (you may take G = 6.67 × 10−11 Nm2 / kg2)
21. A 20 cm long capillary tube dipped in water. The water rises up to 8 cm. If the entire arrangement is put in a freely falling elevator the length of water column in the capillary tube will be
22. If ‘S’ is stress and ‘Y’ is Young’s modulus of material of a wire, the energy stored in the wire per unit volume is
23. Average density of the earth
24. A body of mass m is accelerated uniformly from rest to a speed v in a time T. The instantaneous power delivered to the body as a function of time is given by
25. Consider a car moving on a straight road with a speed of 100 m/s. The distance at which car can be stopped is [μk = 0.5]
26. Which of the following is incorrect regarding the first law of thermodynamics?
27. The figure shows a system of two concentric spheres of radii r₁ and r₂ and temperatures T₁ and T₂ respectively. The radial rate of outflow of heat in a substance between the two concentric spheres is proportional to
28. A system goes from A to B via two processes I and II as shown in figure. If ΔU₁ and ΔU₂ are the changes in internal energies in the processes I and II respectively, then
29. A gaseous mixture consists of 16 g of helium and 16 g of oxygen. The ratio of specific heats of the mixture is
30. The intensity of gamma radiation from a given source is I. On passing through 36 mm of lead, it is reduced to 1/8. The thickness of lead which will reduce the intensity to 1/2 will be
31. The electrical conductivity of a semiconductor increases when electromagnetic radiation of wavelength shorter than 2480 nm is incident on it. The band gap in (eV) for the semiconductor is
32. A photocell is illuminated by a small bright source placed 1 m away. When the same source of light is placed 1/2 m away, the number of electrons emitted by photocathode would
33. Starting with a sample of pure 66Cu, 1/8 of it decays into Zn in 15 minutes. The corresponding half-life is
34. If radius of the 2713Al nucleus is estimated to be 3.6 Fermi then the radius of 12552Te nucleus would be nearly
35. The diagram shows the energy levels for an electron in a certain atom. Which transition shown represents the emission of a photon with the most energy?
36. If the kinetic energy of a free electron doubles, its de-Broglie wavelength changes by the factor
37. In a common base amplifier, the phase difference between the input signal voltage and output voltage is
38. In a full wave rectifier circuit operating from 50 Hz mains frequency, the fundamental frequency in the ripple would be
39. A nuclear transformation is denoted by X(n, α)73Li which of the following is the nucleus of element X?
40. The function sin2(ωt) represents
41. A Young’s double slit experiment uses a monochromatic source. The shape of the interference fringes formed on a screen is
42. Two simple harmonic motions are represented by the equations
y1 = 0.1sin (100πt + π3) and y2 = 0.1cosπt.
The phase difference of the velocity of particle 1 with respect to the velocity of particle 2 is
y1 = 0.1sin (100πt + π3) and y2 = 0.1cosπt.
The phase difference of the velocity of particle 1 with respect to the velocity of particle 2 is
43. A fish looking up through the water sees the outside world contained in a circular horizon. If the refractive index of water is 43 and the fish is 12 cm below the surface, the radius of this circle in cm is
44. Two point white dots are 1 mm apart on a black paper. They are viewed by eye of pupil diameter 3 mm. Approximately, what is the maximum distance at which these dots can be resolved by the eye? [Take wavelength of light = 500 nm]
45. A thin glass (refractive index 1.5) lens has optical power of −5D in air. Its optical power in a liquid medium with refractive index 1.6 will be
46. When two tuning forks (fork 1 and fork 2) are sounded simultaneously, 4 beats per second are heard. Now, some tape is attached on the prong of-the fork 2. When the tuning forks are sounded again, 6 beats per second are heard. If the frequency of fork 1 is 200 Hz; then what was the original frequency of fork 2?
47. If a sample harmonic motion is represented by
d2xdt2 + αx = 0, its time period is
d2xdt2 + αx = 0, its time period is
48. The bob of a simple pendulum is a spherical hollow ball filled with water. A plugged hole near the bottom of the oscillating bob gets suddenly unplugged. During observation, till water is coming out, the time period of oscillation would
49. An observer moves towards a stationary source of sound, with a velocity one-fifth of the velocity of sound. What is the percentage increase in the apparent frequency?
50. If I0 is the intensity of the principal maximum in the single slit diffraction pattern, then what will be its intensity when the slit width is doubled?
51. When an unpolarized light of intensity I0 is incident on a polarizing sheet, the intensity of the light which does not get transmitted is
52. A charged ball B hangs from a silk thread S, which makes an angle θ with a large charged conducting sheet P, as shown in the figure. The surface charge density σ of the sheet is proportional to