4.COMBINED TEST-2 PAPER-2

COMBINED TEST 2 PAPER-2 INSTRUCTIONS SECTION – I (Single Correct Answer Type) This section contains 8 multiple choice questions. Each question has four choices (A), (B), (C) and (D) out of which ONLY ONE is correct. 1. In the figure shown, a small block of mass m moves in fixed semicircular smooth track of radius R in vertical plane. It is released from the top. The maximum centrifugal force on the block at the lowest point of track is. (A) 3 mg (B) 2 mg (C) mg (D) zero 2. Find maximum amplitude for safe SHM(block does not topple during SHM) of a uniform cubical block of side 'a' on a smooth horizontal floor as shown in figure (sptring is massless) : (A) mg (B) 3mg 2K (C) 3mg 4K K (D) 3mg 2K 3. In the figure shown, the pulleys and strings are massless. The acceleration of the block of mass 4m just after the system is released from rest is 3 ( = sin–1 5 ) 2g (A) 5 2g downward (B) 5 upwards (C) 5 g 11 upwards (D) 5 g downwards 11 4. In the figure shown, a light container is kept on a horizontal rough surface of coefficient of friction  = Sh . A very small hole of area S is made at depth 'h'. V Water of volume 'V' is filled in the container. The friction is not sufficient to keep the container at rest. The acceleration of the container initially is V (A) Sh g (B) g (C) zero (D) Sh g V 5. A solid sphere of iron at 2°C is lying at the bottom of a bucket full of water at 2°C. If the temperature of the water is increased to 3°C, the buoyant force on the sphere due to water will. (A) Increase (B) Be unchanged (C) Decrease 6. An ice block at 0°C and of mass m is dropped from height 'h' such that the loss in gravitational potential energy of block is exactly equal to the heat required to just completely melt the ice. Taking latent heat of fusion of ice = 80 cal/gm, acceleration due to gravity = 10 m/s2 and mechanical equivalent of heat = 4.2 J/ Cal. The value of 'h' is (A) 8 m (B) 8 km (C) 33.6 m (D) 33.6 km 7. A wall is moving with constant velocity u towards a fixed source of sound of frequency 'f'. The velocity of sound is 'v'. The wavelength of the sound reflected by the wall is - (A) v f v  u (B) f (C) (C) v  u (D) (D) v  u . v f v  u f 8. Two sources S1 and S2 of same frequency f emits sound. The sources are moving as shown with speed u each. A stationary observer hears that sound. The beat frequency is (v = velocity of sound) (A) (C) 2u2f v2  u2 2uv f v2  u2 (B) (D) 2 v2 f v2  u2 2u f v SECTION – II (Paragraph Type) This section contains 6 mulitiple choice questions relating to three paragraphs with two questions on each pargraph. Each question has four choices (A), (B), (C) and (D) out of which ONLY ONE is correct. Paragraph for Question Nos. 9 to 10 A smooth ball 'A' moving with velocity 'V' collides with another smooth identical ball at rest. After collision both the balls move with same speed with angle between their velocities 60°. No external force acts on the system of balls. 9. The speed of each ball after the collision is (A) V 2 V (B) 3 (C) (C) (D) (D) 10. If the kinetic energy lost is fully converted to heat then heat produced is (A) 1 mV2 3 (B) 2 mV2 3 (C) 0 (D) 1 mV2 6 Paragraph for Question Nos. 11 to 12 A sinusoidal wave travels along a taut string of linear mass density 0.1 g/cm. The particles oscillate along y-direction and wave moves in the positive x-direction. The amplitude and frequency of oscillation are 2mm and 50 Hz respectively. The minimum distance between two particles oscillating in the same phase is 4m. 11. The tension in the string is (in newton) (A) 4000 (B) 400 (C) 25 (D) 250 12. The amount of energy transferred (in Joules) through any point of the string in 5 seconds is 2 (A) 10 2 (B) 50 2 (C) 5 (D) Cannot be calculated because area of cross-section of string is not given. Paragraph for Question Nos. 13 to 14 A small mass slides down a fixed inclined plane of inclination  with the horizontal. The co-efficient of friction is  = 0 x where x is the distance through which the mass slides down and 0 is a constant. 13. The distance covered by the mass before it stops is: 2 4 1 1 (A)  tan  (B)  tan  (C) 2  tan  (D)  tan  0 0 0 0 14. The heat produced during the half journey of the particle is: (A) mg cos  2 0 tan2  (B) mg cos  4 0 tan2  (C) mg cos  8 0 tan2  (D) none of these SECTION — III (Multiple Correct Answer(s) Type) This section contains 6 multiple choice questions. Each question has four choices (A), (B), (C) and (D) out of which ONE or MORE may be correct. 15. A particle is subjected to two simple harmonic motions along x and y axis according to, x = 3 sin 100 t, (A) The path of the particle will be ellipse and it is moving in clockwise direction. (B) Motion of particle will be on a straight line. (C) Motion will be a simple harmonic motion with amplitude 5. (D) Phase difference between two motions is  . 2 16. A thin uniform rigid rod of mass m and length 𝑙 is in mechanical equilibrium under the constraints of horizontal and vertical rough surfaces. Then select correct option(s): (A) The net torque of normal reactions about O is equal to mg (B) The net torque of friction about O is zero. 𝑙 cos. 2 (C) The net torque of normal reactions is numerically equal to net torque of frictional forces about the CM of road. (D) none of these 17. An ideal spring is permanently connected between two blocks of masses m and M. The (blocks + spring) system can move over a frictionless horizontal table along a straight line along the length of the spring as shown in figure. The blocks are brought nearer to compress the spring and then released. In the subsequent motion. (A) Initially they move in opposite direction with speeds inversly proportional to the their masses. (B) The ratio of their speeds remains constant in subsequent motion (C) Linear momentum and energy of the system remain conserved. (D) The two blocks will oscillate about their centre of mass which will remain stationary with respect to ground frame. 18. A monoatomic ideal gas undergoes a cyclic process ABCDEA as shown in the P-V diagram. (BC is isothermal and P3V1 < P1V3). Then which of the following curve(s) is/are correctly converted : (A) (B) (C) (D) 19. Find the thickness of the cubical object using the defective vernier calliper main scale has mm marks and 10 divisions of vernier scale coincide with 9 divisions of main scale. (A) 13.8 mm (B) 13.5 mm (C) 14.1 mm (D) 13.0 mm 20. A particle moving with kinetic energy = 3 J makes an elastic head-on collision with a stationary particle which has twice its mass. During the impact : (A) the minimum kinetic energy of the system is 1 J (B) the maximum elastic potential energy of the system is 2 J (C) momentum and total energy are conserved at every instant (D) the ratio of kinetic energy to potential energy of the system first decreases and then increases. ANSWER KEY TO COMBINED TEST - 02 (PAPER - 2) 1. (B) 2. (B) 3. (D) 4. (D) 5. (A) 6. (D) 7. (D) 8. (C) 9. (C) 10. (D) 11. (B) 12. (C) 13. (A) 14. (A) 15. (B,C) 16. (A,B,C) 17. (A,B,C,D) 18. (A,B) 19. (B) 20. (A,B,C,D) PART-2

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