IIT JEE –Past papers: IIT JEE –Past papers PHYSICS- UNSOLVED PAPER - 1984
SECTION – I: SECTION – I Single Correct Answer Type In each of the statement below, several alternatives are given. In some cases, more than one alternative may be correct. Select all the correct alternative(s) in each case, and write sown the corresponding letter(s) (a),(b) (c) or (d) in your answer book, For each part, marks will be given only if all the correct alternatives are selected:
Problem: 01 L, C and R represent the physical quantities, inductance, capacitance and resistance respectively. The combinations which have the dimension of frequency are: 1/RC R/L C/L Problem
Problem: Problem 02 A body is moved along a straight line by a machine delivering constant Power. The distance moved by the body in time t is proportional to. t 1/2 t 3/4 t 3/2 t 2
Problem: Problem 03 A transverse wave is described by the equation The maximum particle velocity is equal to four times the wave velocity if a. b. c. d.
Problem: Problem 04 White light is used to illuminate the two slits in a Young’s double slit experiment. The separation between the slits is b and the screen is at a distance d (>> b ) from the slits. At a point on the screen directly in front of one of the slits, certain wavelengths are missing. Some ob these missing wavelength are a. b. c. d.
Problem: Problem 05 Two equal negative charge –q are fixed at the points (0, a ) and (0, - a ) on the y-axis. A positive charge Q is released from rest at the point (2 a , 0) on the x-axis. The charge Q will Execute simple harmonic motion about the origin Move to the origin and remain at rest Move to infinity Execute oscillatory but not simple harmonic motion
Problem: Problem 06 From the following equation pick out the possible nuclear fusion reactions: a. b. c. d.
Problem: Problem 07 In the Bohr model of the hydrogen atom The radius of the n th orbit is proportional to n 2 The total energy of the electron in the nth orbit is inversely proportional to n The angular momentum of the electron of the electron in any orbit is an integral multiple of h/2 The magnitude of the potential energy of the electron in any orbit is greater than its kinetic energy
Problem: Problem 08 Select the correct statements from the following: A diode can be used as a rectifier A triode cannot be use be a rectifier The current in a diode is always proportional to the applied voltage The liner portion of the I-V characteristic of a triode is used for amplification without distortion
Problem: Problem 09 At room temperature, the rms speed of the molecules of a certain diatomic gas is found to be 1930 m/s the gas is H 2 F 2 O 2 CI 2
SECTION – II: SECTION – II Fill in the blanks Read the following statements carefully. Indicate the sub-division number and write down the matter corresponding to each blank strictly in the order in which it appear in the statement:
Problem: 01 The numerical value of the angular velocity of rotation of the earth should be ________ red/s in order to make the effective acceleration due of gravity equal to zero at the equator Problem
Problem: Problem 02 A uniform cube of side a and mass m rests on a rough horizontal table. A horizontal force F is applied normal to one of the faces at a point that is directly above the centered of the face, at a height 3a/4 above the base. The minimum value of f for which the cube begins to tip about an edge is _______________ (Assume that the cube does not slide).
Problem: Problem 03 A block of mass 1 kg lies on a horizontal surface in a truck. The coefficient of static friction between the block and the surface is 0.6. If the acceleration of the truck is 5 m/s 2 , the frictional force acting on the block is ________ N.
Problem: Problem 04 Four persons K, L, M, and N are initially at the four corners of a square of side d. Each persons now moves with a uniform speed v in such a way that K always moves directly towards L, L directly towards M, M directly towards N and N directly toward K. The four persons will meet at a time _________.
Problem: Problem 05 One mole of a monatomic ideal gas is mixed with one mole of a diatomic ideal gas. The molar heat capacity of the mixture at constant volume is __________ _
Problem: Problem 06 Sound waves of frequency 660 Hz fall normally on a perfectly reflecting wall. The shortest distance from the wall at which the air particles have the maximum amplitude of vibration is ___________ m.
Problem: Problem 07 Five identical capacitor plates, each of area A, are arranged such that adjacent plates are a distance d apart. The plates are connected to a source of emf V as shown in Fig. 1984.1. The charge on plate 1____________ and that on plate 4 is ___________.
Problem: Problem 08 Figure 1984.2 shows lines of constant potential in a region in which an electric field is present. The values of the potential are written in brackets. Of the points A, B, and C, the magnitude of the electric field is greatest at the point _____________ .
Problem: Problem 09 The maximum kinetic energy of electrons emitted in the photoelectric effect is linearly dependent on the ___________ of the incident radiation.
Problem: Problem 10 A neutron, a proton, an electron and an alpha particle enter a region of constant magnetic field with equal velocities. The magnetic field is along the inward normal to the plane of the paper. The tracks of the particles are labeled in Fig. 1984.3. The electron follows track __________ and the alpha particle follows track __________ .
SECTION – III: SECTION – III Each of which either true or False State whether the following are TRUE or FALSE. Give reasons in brief in support of your answers. Marks will be awarded only if the correct reasons are given:
Problem: 01 A projectile fired from the ground follows a parabolic path. The speed of the projectile is minimum at the top of its path. Problem
Problem: Problem 02 A simple pendulum with a bob of mass m swings with an angular amplitude of. When its angular displacement is , the tension in the string is greater than mg cos
Problem: Problem 03 It is possible to put an artificial satellite into an orbit in such a way that it will always remain directly over New Delhi.
Problem: Problem 04 The pulley arrangements of Fig. 1984.4(a) and b) are identical. The mass of the rope is negligible. In Fig. 1984.4(a), the mass m is lifted by attaching a mass 2m to the other end of the rope .In fig. 1984.4(b), m is lifted up by pulling the other end of the rope with a constant downward force F = 2mg. The acceleration of m is the same in both cases.
Problem: Problem 05 A plane wave of sound traveling in air is incident upon a plane water surface. The angle of incidence is 60 0 . Assuming Snell’s law to be valid for sound waves, it follows that the sound wave will be refracted into the water away from the normal. Given: Velocities of sound in air and medium are 330 m/s and 1400 m/s, respectively.
Problem: Problem 06 The two slits in a Young’s double slit experiment are illuminated by two different sodium lamps emitting light of the same wavelength . No interference pattern will be observed on the screen
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