1. IIT JEE –Past papers PHYSICS- UNSOLVED PAPER - 1990

2. SECTION – I Single Correct Answer Type In each of the statements given below, four alternatives are given. In some cases, more than one alternative is correct. Select the correct alternative(s) in each case and write down the corresponding letter(s)(a),(b),(c) or (d) in your answer book. For each part marks will be awarded only if all the correct alternatives are selected and written:

3. 01 Problem When a bicycle is in motion, for force of friction exerted by the ground on the two wheels is such that it acts. In the backward direction on the front wheel and in the forward direction on the rear wheel. In the Forward direction on the front wheel and in the backward direction on the rear wheel. In the backward direction on both the front and the rear wheels. In the forward direction on both the front and the rear wheels

4. Problem 02 A particle of mass m is projected with a velocity v making an angle of 450 With the horizontal. The magnitude of the angular momentum of the projectile about the point of projection when the particle is at its maximum height h is Zero b. c. d.

5. Problem 03 A uniform cylinder of length L and mass M having cross-sectional area A is suspended, with its length vertical, from a fixed point by a mass less spring, such that it is half-submerged in a liquid of density pat equilibrium position. When the cylinder is given a small downward push and released it starts oscillating vertically with a frequency of oscillation of the cylinder is a. b. c. d.

6. Problem 04 When an ideal diatomic gas is heated at constant pressure, the fraction of the heat energy supplied which increases the internal energy of the gas is a. b. c. d.

7. Problem 05 A thin prism P1with angle 40and made from glass of refractive index 1.54 is combined with another thin prism P2 made from glass of refractive index 1.72 to produce dispersion without deviation. The angle of the prism P2 is 5.330 40 30 2.60

8. Problem 06 A wave is represented by the equation Where x is in meters and t in seconds. The expression represents A wave traveling in the positive x direction with a velocity 1.5 m/s A wave traveling in the negative x direction with a velocity 1.5m/s A wave traveling in the negative x direction having a wavelength 0.2m A wave traveling in the positive x direction having a wavelength 0.2m

9. Problem 07 Seven capacitor each of capacitance 2 are to be connected in a configuration to obtain an effective capacitance of (10/11) which of the combination (s) shown in fig. 1990.1 will achieve the desired result?

10. SECTION – II Fill in the balks Fill in the blanks in the following statement. Indicate the sub-division number and write down your answer corresponding to each blank strictly in the order in which it appear in the statements.

11. 01 Problem A wire ABCDEF (with each side of length L) bent as shown in Fig. 1990.2 and carrying a current I is placed in a uniform magnetic induction B parallel to the positive y –direction. The force experienced by the wire is _________ in the _________ direction.

12. Problem 02 The amplitude of a wave disturbance propagating in the positive x-axis is given by y = 1/(1 + x2) at time t = 0 and by y =1/[1+(x – 1)2 at t = 2 seconds , where x and y are in meters . The shape of the wave disturbance does not change during the propagation. The velocity of the wave is _________ m/s.

13. Problem 03 ___________ biasing of the p-n junction offers high resistance to current flow across the junction. This biasing is obtained by connecting the p-side to the __________ terminal of the battery.

14. Problem 04 The wavelength of the characteristic X-ray Ka line emitted by a hydrogen-like element is 0.32 Å . The wavelength of the line emitted by the same element will be ______.

15. SECTION – III Mach the following Column I give three physical quantities. Select the appropriate units for these from the choices given in column II. Some of the physical quantities may be have more than one choice

16. 01 Problem I II Capacitance ohm second Inductance coulomb2 joule-1 Magnetic induction coulomb (volt)-1 Newton (ampere meter)-1 Volt second (ampere)-1

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