Page 1 (1) PHYSICS Choose the correct answer : Topics Covered in Various Subjects : Physics : Work, Energy and Power; System of Particles and Rotational Motion Chemistry : States of Matter: Gases & Liquids ; Thermodynamics Botany : Morphology of Flowering Plants; Anatomy of Flowering Plants Zoology : Structural Organization in Animals (a) Animal tissues (b) Animal Morphology MM : 800 Regular Classroom Test - 3 Time : 3 Hrs. (REGULAR MEDICAL - 201 1) 08/09/2010 Regd. Office : Aakash T ower, Plot No.-4, Sec-11, MLU, Dwarka, New Delhi-110075 Ph.: 011-47623456 Fax : 011-47623472 Premier Institute in India for Medical Entrance Exams. RM CODE-A 1. The example of nonzero work is (1) Work done by a coolie in lifting up a load, against gravity on a horizontal platform (2) Work done in holding a heavy weight by a weight lifter on his shoulders (3) Work done by gravitational force in revolution of a satellite around the earth (4) All of these 2. A rod of mass 10 kg and length 2 m is lying on a horizontal table. The minimum work done in making it stand vertically about one end will be (1) 200 J (2) 100 J (3) 50 J (4) 400 J 3. Work done by frictional force in pure rolling motion is (1) Positive (2) Negative (3) Positive or negative depends on the condition (4) Zero 4. A body of mass m tied to a string is moving in complete vertical circle. The difference in maximum and minimum tension in the string is (1) mg (2) 2mg (3) 3mg (4) 6mg 5. A bob of mass m is attached with a mass less string of length L as shown in figure. String is hung from a fixed point. Initial speed of ball is u = 2 gL . T ension in the string when it becomes horizontal is m u L (1) mg (2) 2 mg (3) Zero (4) 3 mg 6. The value of the coefficient of restitution for perfectly inelastic collision is (1) Equal to 1 (2) Greater than 1 (3) Zero (4) Less than 1 Page 2 (1) PHYSICS Choose the correct answer : Topics Covered in Various Subjects : Physics : Work, Energy and Power; System of Particles and Rotational Motion Chemistry : States of Matter: Gases & Liquids ; Thermodynamics Botany : Morphology of Flowering Plants; Anatomy of Flowering Plants Zoology : Structural Organization in Animals (a) Animal tissues (b) Animal Morphology MM : 800 Regular Classroom Test - 3 Time : 3 Hrs. (REGULAR MEDICAL - 201 1) 08/09/2010 Regd. Office : Aakash T ower, Plot No.-4, Sec-11, MLU, Dwarka, New Delhi-110075 Ph.: 011-47623456 Fax : 011-47623472 Premier Institute in India for Medical Entrance Exams. RM CODE-A 1. The example of nonzero work is (1) Work done by a coolie in lifting up a load, against gravity on a horizontal platform (2) Work done in holding a heavy weight by a weight lifter on his shoulders (3) Work done by gravitational force in revolution of a satellite around the earth (4) All of these 2. A rod of mass 10 kg and length 2 m is lying on a horizontal table. The minimum work done in making it stand vertically about one end will be (1) 200 J (2) 100 J (3) 50 J (4) 400 J 3. Work done by frictional force in pure rolling motion is (1) Positive (2) Negative (3) Positive or negative depends on the condition (4) Zero 4. A body of mass m tied to a string is moving in complete vertical circle. The difference in maximum and minimum tension in the string is (1) mg (2) 2mg (3) 3mg (4) 6mg 5. A bob of mass m is attached with a mass less string of length L as shown in figure. String is hung from a fixed point. Initial speed of ball is u = 2 gL . T ension in the string when it becomes horizontal is m u L (1) mg (2) 2 mg (3) Zero (4) 3 mg 6. The value of the coefficient of restitution for perfectly inelastic collision is (1) Equal to 1 (2) Greater than 1 (3) Zero (4) Less than 1 (2) 7. A ball of mass 3 kg is initially at rest. Due to explosion, it divides into two parts of 2 kg and 1 kg. If kinetic energy of heavier part is 8 J, then energy released in the explosion is (1) 16 J (2) 24 J (3) 20 J (4) 32 J 8. An automobile of mass m is accelerates from rest whose engine supplies a constant power P. The velocity attained after time t is proportional to (1) t 3/2 (2) t 1/2 (3) t (4) t 2 9. A ball is dropped from height 32 cm above ground level. If the coefficient of restitution between the ball and ground is 0.5 then, to what maximum height will it rise after first collision? (1) 16 m (2) 8 m (3) 4 m (4) 1 m 10. A wire of mass m and length l is bent in the form of an arc of a circle subtends an angle ? at its centre. Its moment of inertia (I) about an axis through centre of circle and normal to the plane of circle varies as (1) I ? ? (2) I ? ? –2 (3) (4) I ? ? 0 1 1. A disc is rolling without slipping on a horizontal smooth surface. Ratio of its translational kinetic energy to total kinetic energy is (1) (2) 5 3 (3) 3 2 (4) 7 5 12. A body is rolling down a rough inclined plane. Which force is responsible for increase in rotational kinetic energy? (1) Normal reaction by plane on body (2) Weight of the body (3) Frictional force (4) Gravitational force 13. The F - x graph of a particle of mass 1 kg is shown in the figure. If the particle begins to move from rest at x = 0, its velocity at x = 3 is O x F 10 N 3 m 6 m (1) (2) (3) (4) 14. Two springs having spring constants K 1 and K 2 are stretched by equal forces. The ratio of respective potential energies stored in them will be (1) 1 : 1 (2) K 1 : K 2 (3) K 2 : K 1 (4) : 15. A light ball is thrown with a speed of 5 m/s in a gravity free space and a very heavy lift is moving with a speed of 10 m/s as shown in the figure. If perfectly elastic collision takes place between the ball and floor of lift, then speed of the ball after collision (1) 15 m/s (2) 25 m/s (3) 5 m/s (4) 20 m/s 16. Three forces of equal magnitude F act on a moving body as shown. The body displaces by displacement S in a duration of t second. The kinetic energy of body increases by (assuming no other force or field) F F F S ? ? ? (1) 3FS (2) 2FS (3) FS (4) Zero 17. On a foggy day, drivers of two cars spot in front of each other when 70 m apart. They were travelling at 66 kmph and 60 kmph. Both apply brakes simultaneously which retard the cars at the rate of 5 m/s 2 each. Which of the following statements is correct? (1) The collision will be averted (2) The collision will take place (3) Their relative acceleration is zero (4) They will just collide 18. A uniform rod AB of length L and mass m is pivoted at end AB and is released from a horizontal position as shown in figure. Angular acceleration of rod about A at this instant is A B m, L (1) L g 2 (2) L g 2 3 (3) L g 3 (4) L g 3 2 Page 3 (1) PHYSICS Choose the correct answer : Topics Covered in Various Subjects : Physics : Work, Energy and Power; System of Particles and Rotational Motion Chemistry : States of Matter: Gases & Liquids ; Thermodynamics Botany : Morphology of Flowering Plants; Anatomy of Flowering Plants Zoology : Structural Organization in Animals (a) Animal tissues (b) Animal Morphology MM : 800 Regular Classroom Test - 3 Time : 3 Hrs. (REGULAR MEDICAL - 201 1) 08/09/2010 Regd. Office : Aakash T ower, Plot No.-4, Sec-11, MLU, Dwarka, New Delhi-110075 Ph.: 011-47623456 Fax : 011-47623472 Premier Institute in India for Medical Entrance Exams. RM CODE-A 1. The example of nonzero work is (1) Work done by a coolie in lifting up a load, against gravity on a horizontal platform (2) Work done in holding a heavy weight by a weight lifter on his shoulders (3) Work done by gravitational force in revolution of a satellite around the earth (4) All of these 2. A rod of mass 10 kg and length 2 m is lying on a horizontal table. The minimum work done in making it stand vertically about one end will be (1) 200 J (2) 100 J (3) 50 J (4) 400 J 3. Work done by frictional force in pure rolling motion is (1) Positive (2) Negative (3) Positive or negative depends on the condition (4) Zero 4. A body of mass m tied to a string is moving in complete vertical circle. The difference in maximum and minimum tension in the string is (1) mg (2) 2mg (3) 3mg (4) 6mg 5. A bob of mass m is attached with a mass less string of length L as shown in figure. String is hung from a fixed point. Initial speed of ball is u = 2 gL . T ension in the string when it becomes horizontal is m u L (1) mg (2) 2 mg (3) Zero (4) 3 mg 6. The value of the coefficient of restitution for perfectly inelastic collision is (1) Equal to 1 (2) Greater than 1 (3) Zero (4) Less than 1 (2) 7. A ball of mass 3 kg is initially at rest. Due to explosion, it divides into two parts of 2 kg and 1 kg. If kinetic energy of heavier part is 8 J, then energy released in the explosion is (1) 16 J (2) 24 J (3) 20 J (4) 32 J 8. An automobile of mass m is accelerates from rest whose engine supplies a constant power P. The velocity attained after time t is proportional to (1) t 3/2 (2) t 1/2 (3) t (4) t 2 9. A ball is dropped from height 32 cm above ground level. If the coefficient of restitution between the ball and ground is 0.5 then, to what maximum height will it rise after first collision? (1) 16 m (2) 8 m (3) 4 m (4) 1 m 10. A wire of mass m and length l is bent in the form of an arc of a circle subtends an angle ? at its centre. Its moment of inertia (I) about an axis through centre of circle and normal to the plane of circle varies as (1) I ? ? (2) I ? ? –2 (3) (4) I ? ? 0 1 1. A disc is rolling without slipping on a horizontal smooth surface. Ratio of its translational kinetic energy to total kinetic energy is (1) (2) 5 3 (3) 3 2 (4) 7 5 12. A body is rolling down a rough inclined plane. Which force is responsible for increase in rotational kinetic energy? (1) Normal reaction by plane on body (2) Weight of the body (3) Frictional force (4) Gravitational force 13. The F - x graph of a particle of mass 1 kg is shown in the figure. If the particle begins to move from rest at x = 0, its velocity at x = 3 is O x F 10 N 3 m 6 m (1) (2) (3) (4) 14. Two springs having spring constants K 1 and K 2 are stretched by equal forces. The ratio of respective potential energies stored in them will be (1) 1 : 1 (2) K 1 : K 2 (3) K 2 : K 1 (4) : 15. A light ball is thrown with a speed of 5 m/s in a gravity free space and a very heavy lift is moving with a speed of 10 m/s as shown in the figure. If perfectly elastic collision takes place between the ball and floor of lift, then speed of the ball after collision (1) 15 m/s (2) 25 m/s (3) 5 m/s (4) 20 m/s 16. Three forces of equal magnitude F act on a moving body as shown. The body displaces by displacement S in a duration of t second. The kinetic energy of body increases by (assuming no other force or field) F F F S ? ? ? (1) 3FS (2) 2FS (3) FS (4) Zero 17. On a foggy day, drivers of two cars spot in front of each other when 70 m apart. They were travelling at 66 kmph and 60 kmph. Both apply brakes simultaneously which retard the cars at the rate of 5 m/s 2 each. Which of the following statements is correct? (1) The collision will be averted (2) The collision will take place (3) Their relative acceleration is zero (4) They will just collide 18. A uniform rod AB of length L and mass m is pivoted at end AB and is released from a horizontal position as shown in figure. Angular acceleration of rod about A at this instant is A B m, L (1) L g 2 (2) L g 2 3 (3) L g 3 (4) L g 3 2 (3) 19. If a conservative force is acting on a system, then work done by this force is equal to (1) Change in kinetic energy (2) Change in potential energy (3) Negative of charge in potential energy (4) Change in mechanical energy 20. In a head on inelastic collision of two balls travelling in same direction first ball stops after collision. If coefficient of restitution is 0.8 and velocities of balls before collision are 10 ms –1 and 5 ms –1 respectively then, the velocity of second ball after collision will be (1) 5 ms –1 (2) 8 ms –1 (3) 4 ms –1 (4) 12 ms –1 21. A ball of mass 500 g moving with speed 2 m/s collide to a horizontal floor making an angle of 45° with vertical. If coefficient of restitution is 1 3 , then the angle made by the ball with vertical, after collision is (1) 60° (2) 30° (3) 45° (4) 37° 22. A small block is released from point A as shown in the figure. It slides down the smooth surface AB and leaves contact with the surface at B horizontally. The horizontal range (R) of this block will be B H R m H/2 (1) (2) H (3) 4 H (4) 2 H 23. A very heavy block collides elastically to a very light stationary block on a smooth horizontal surface. After collision the velocity of light body will be (1) Zero (2) Same as the velocity of heavy block before collision (3) Twice of the velocity of heavy block before collision (4) Very high as compared to the velocity of heavy block before collision 24. Parallel axis and perpendicular axes theorems are respectively applicable for (1) Thin lamina only, thin lamina only (2) All bodies, thin lamina only (3) All bodies, all bodies (4) Thin lamina only, all bodies 25. Which of the following statement is incorrect? (1) If external torque on the system about an axis is zero, then the angular momentum about that axis is conserved (2) If external torque on the system about an axis is zero, then rotational kinetic energy about that axis is conserved (3) Any internal interaction between parts of the system cannot alter its total angular momentum (4) A particle moving parallel to x-axis or y-axis with constant velocity, then its angular momentum about origin will remain constant 26. A uniform rod AB of mass m and length 2a is falling freely without rotation under gravity with AB horizontal. Suddenly the end A is fixed when the speed of rod is v. The angular speed with which the rod begins to rotate is (1) 2 v a (2) (3) (4) 27. A disc and a ring of same mass and same radius are allowed for pure rolling on an rough inclined plane from same height. Ratio of their acceleration down the plane is (1) 4 : 3 (2) 3 : 4 (3) 5 : 2 (4) 2 : 5 28. A diver exhibits some rotations in air before touching the surface of water. In this case he uses the principle of (1) Conservations of linear momentum (2) Newton’s laws of motion (3) Conservation of angular momentum (4) Impulse momentum theorem 29. A body of mass 10 kg is dropped form rest from a height 20 m. If it reaches the ground with 10 m/s, then work done by air resistance is (1) + 1500 J (2) – 1500 J (3) + 500 J (4) – 500 J Page 4 (1) PHYSICS Choose the correct answer : Topics Covered in Various Subjects : Physics : Work, Energy and Power; System of Particles and Rotational Motion Chemistry : States of Matter: Gases & Liquids ; Thermodynamics Botany : Morphology of Flowering Plants; Anatomy of Flowering Plants Zoology : Structural Organization in Animals (a) Animal tissues (b) Animal Morphology MM : 800 Regular Classroom Test - 3 Time : 3 Hrs. (REGULAR MEDICAL - 201 1) 08/09/2010 Regd. Office : Aakash T ower, Plot No.-4, Sec-11, MLU, Dwarka, New Delhi-110075 Ph.: 011-47623456 Fax : 011-47623472 Premier Institute in India for Medical Entrance Exams. RM CODE-A 1. The example of nonzero work is (1) Work done by a coolie in lifting up a load, against gravity on a horizontal platform (2) Work done in holding a heavy weight by a weight lifter on his shoulders (3) Work done by gravitational force in revolution of a satellite around the earth (4) All of these 2. A rod of mass 10 kg and length 2 m is lying on a horizontal table. The minimum work done in making it stand vertically about one end will be (1) 200 J (2) 100 J (3) 50 J (4) 400 J 3. Work done by frictional force in pure rolling motion is (1) Positive (2) Negative (3) Positive or negative depends on the condition (4) Zero 4. A body of mass m tied to a string is moving in complete vertical circle. The difference in maximum and minimum tension in the string is (1) mg (2) 2mg (3) 3mg (4) 6mg 5. A bob of mass m is attached with a mass less string of length L as shown in figure. String is hung from a fixed point. Initial speed of ball is u = 2 gL . T ension in the string when it becomes horizontal is m u L (1) mg (2) 2 mg (3) Zero (4) 3 mg 6. The value of the coefficient of restitution for perfectly inelastic collision is (1) Equal to 1 (2) Greater than 1 (3) Zero (4) Less than 1 (2) 7. A ball of mass 3 kg is initially at rest. Due to explosion, it divides into two parts of 2 kg and 1 kg. If kinetic energy of heavier part is 8 J, then energy released in the explosion is (1) 16 J (2) 24 J (3) 20 J (4) 32 J 8. An automobile of mass m is accelerates from rest whose engine supplies a constant power P. The velocity attained after time t is proportional to (1) t 3/2 (2) t 1/2 (3) t (4) t 2 9. A ball is dropped from height 32 cm above ground level. If the coefficient of restitution between the ball and ground is 0.5 then, to what maximum height will it rise after first collision? (1) 16 m (2) 8 m (3) 4 m (4) 1 m 10. A wire of mass m and length l is bent in the form of an arc of a circle subtends an angle ? at its centre. Its moment of inertia (I) about an axis through centre of circle and normal to the plane of circle varies as (1) I ? ? (2) I ? ? –2 (3) (4) I ? ? 0 1 1. A disc is rolling without slipping on a horizontal smooth surface. Ratio of its translational kinetic energy to total kinetic energy is (1) (2) 5 3 (3) 3 2 (4) 7 5 12. A body is rolling down a rough inclined plane. Which force is responsible for increase in rotational kinetic energy? (1) Normal reaction by plane on body (2) Weight of the body (3) Frictional force (4) Gravitational force 13. The F - x graph of a particle of mass 1 kg is shown in the figure. If the particle begins to move from rest at x = 0, its velocity at x = 3 is O x F 10 N 3 m 6 m (1) (2) (3) (4) 14. Two springs having spring constants K 1 and K 2 are stretched by equal forces. The ratio of respective potential energies stored in them will be (1) 1 : 1 (2) K 1 : K 2 (3) K 2 : K 1 (4) : 15. A light ball is thrown with a speed of 5 m/s in a gravity free space and a very heavy lift is moving with a speed of 10 m/s as shown in the figure. If perfectly elastic collision takes place between the ball and floor of lift, then speed of the ball after collision (1) 15 m/s (2) 25 m/s (3) 5 m/s (4) 20 m/s 16. Three forces of equal magnitude F act on a moving body as shown. The body displaces by displacement S in a duration of t second. The kinetic energy of body increases by (assuming no other force or field) F F F S ? ? ? (1) 3FS (2) 2FS (3) FS (4) Zero 17. On a foggy day, drivers of two cars spot in front of each other when 70 m apart. They were travelling at 66 kmph and 60 kmph. Both apply brakes simultaneously which retard the cars at the rate of 5 m/s 2 each. Which of the following statements is correct? (1) The collision will be averted (2) The collision will take place (3) Their relative acceleration is zero (4) They will just collide 18. A uniform rod AB of length L and mass m is pivoted at end AB and is released from a horizontal position as shown in figure. Angular acceleration of rod about A at this instant is A B m, L (1) L g 2 (2) L g 2 3 (3) L g 3 (4) L g 3 2 (3) 19. If a conservative force is acting on a system, then work done by this force is equal to (1) Change in kinetic energy (2) Change in potential energy (3) Negative of charge in potential energy (4) Change in mechanical energy 20. In a head on inelastic collision of two balls travelling in same direction first ball stops after collision. If coefficient of restitution is 0.8 and velocities of balls before collision are 10 ms –1 and 5 ms –1 respectively then, the velocity of second ball after collision will be (1) 5 ms –1 (2) 8 ms –1 (3) 4 ms –1 (4) 12 ms –1 21. A ball of mass 500 g moving with speed 2 m/s collide to a horizontal floor making an angle of 45° with vertical. If coefficient of restitution is 1 3 , then the angle made by the ball with vertical, after collision is (1) 60° (2) 30° (3) 45° (4) 37° 22. A small block is released from point A as shown in the figure. It slides down the smooth surface AB and leaves contact with the surface at B horizontally. The horizontal range (R) of this block will be B H R m H/2 (1) (2) H (3) 4 H (4) 2 H 23. A very heavy block collides elastically to a very light stationary block on a smooth horizontal surface. After collision the velocity of light body will be (1) Zero (2) Same as the velocity of heavy block before collision (3) Twice of the velocity of heavy block before collision (4) Very high as compared to the velocity of heavy block before collision 24. Parallel axis and perpendicular axes theorems are respectively applicable for (1) Thin lamina only, thin lamina only (2) All bodies, thin lamina only (3) All bodies, all bodies (4) Thin lamina only, all bodies 25. Which of the following statement is incorrect? (1) If external torque on the system about an axis is zero, then the angular momentum about that axis is conserved (2) If external torque on the system about an axis is zero, then rotational kinetic energy about that axis is conserved (3) Any internal interaction between parts of the system cannot alter its total angular momentum (4) A particle moving parallel to x-axis or y-axis with constant velocity, then its angular momentum about origin will remain constant 26. A uniform rod AB of mass m and length 2a is falling freely without rotation under gravity with AB horizontal. Suddenly the end A is fixed when the speed of rod is v. The angular speed with which the rod begins to rotate is (1) 2 v a (2) (3) (4) 27. A disc and a ring of same mass and same radius are allowed for pure rolling on an rough inclined plane from same height. Ratio of their acceleration down the plane is (1) 4 : 3 (2) 3 : 4 (3) 5 : 2 (4) 2 : 5 28. A diver exhibits some rotations in air before touching the surface of water. In this case he uses the principle of (1) Conservations of linear momentum (2) Newton’s laws of motion (3) Conservation of angular momentum (4) Impulse momentum theorem 29. A body of mass 10 kg is dropped form rest from a height 20 m. If it reaches the ground with 10 m/s, then work done by air resistance is (1) + 1500 J (2) – 1500 J (3) + 500 J (4) – 500 J (4) 30. A body falling vertically downwards under gravity breaks in two parts of unequal masses. The centre of mass of the two parts taken together (1) Shifts horizontally towards heavier piece (2) Shifts horizontally towards lighter piece (3) Does not shift horizontally (4) Shifts vertically upward 31. Let F ext represents the sum of all external forces acting on the particles of the system. If F ext = 0, then which of the following is incorrect? (1) Acceleration of center of mass must be zero (2) Velocity of center of mass must be zero (3) Total momentum of system must be constant (4) Total kinetic energy of the system may change 32. Two bodies A and B have moment of interia I 1 and I 2 respectively . If both have same angular momenta, then their rotational kinetic energies are in the ratio (1) (2) (3) (4) 33. A body P moving with momentum collides with another body Q moving with momentum . After collision body P moves with momentum . Now momentum of body Q becomes (1) ˆ 6 j (2) (3) (4) 34. A string is wrapped around the circumference of a pulley of radius R. The moment of inertia of the pulley is I about horizontal axis. A weight Mg is attached to the end of the string and is released from rest. After falling through a distance H, the velocity of the wheel will be (1) (2) 1 2 2 2 2 ?? ?? ??? MgHR IMR (3) 1 2 2 2 4 ?? ?? ??? MgHR IMR (4) 1 2 2 2 2( ) ?? ?? ? ?? MgHR IMR 35. A thin rod of length L and mass m rotates with angular velocity ? in a horizontal plane about a vertical axis passing through its one end. Its rotational kinetic energy is (1) 22 1 24 mL ? (2) (3) (4) 36. A particle of mass 1 kg is moving in x-y plane with velocity m/s. The angular momentum of the particle about z-axis, when it is at a point (3, 4) m is (in SI units) (1) ˆ 25 k (2) – (3) (4) Zero 37. A force ˆ Fk ? acts at O, the origin of the coordinate system. The torque about the point (2, –2) is (1) (2) ) ˆ ˆ ( 2 j i F ? (3) ) ˆ ˆ ( 2 j i F ? ? (4) ) ˆ ˆ ( 2 j i F ? 38. Suppose that due to melting of the polar ice, the moment of inertia of the earth about its axis of rotation increases by 1%, then duration of the solar day will (1) Increase by 14.4 minute (2) Decrease by 14.4 minute (3) Increase by 14.4 second (4) Decrease by 14.4 second 39. A point object of mass m is kept at (a, 0). What mass should be kept at (–3a, 0), so that centre of mass lies at origin? (1) m (2) 2m (3) 3 m (4) 3m 40. A uniform circular disc of radius R has its centre at origin O as shown. If a circular groove of radius R/2 is made, the coordinates of the centre of mass of the remaining part is (1) ? ? ? ? ? ? 0 , 6 R (2) ? ? ? ? ? ? 6 , 0 R (3) ? ? ? ? ? ? 0 , 3 R (4) ? ? ? ? ? ? 3 , 0 R Page 5 (1) PHYSICS Choose the correct answer : Topics Covered in Various Subjects : Physics : Work, Energy and Power; System of Particles and Rotational Motion Chemistry : States of Matter: Gases & Liquids ; Thermodynamics Botany : Morphology of Flowering Plants; Anatomy of Flowering Plants Zoology : Structural Organization in Animals (a) Animal tissues (b) Animal Morphology MM : 800 Regular Classroom Test - 3 Time : 3 Hrs. (REGULAR MEDICAL - 201 1) 08/09/2010 Regd. Office : Aakash T ower, Plot No.-4, Sec-11, MLU, Dwarka, New Delhi-110075 Ph.: 011-47623456 Fax : 011-47623472 Premier Institute in India for Medical Entrance Exams. RM CODE-A 1. The example of nonzero work is (1) Work done by a coolie in lifting up a load, against gravity on a horizontal platform (2) Work done in holding a heavy weight by a weight lifter on his shoulders (3) Work done by gravitational force in revolution of a satellite around the earth (4) All of these 2. A rod of mass 10 kg and length 2 m is lying on a horizontal table. The minimum work done in making it stand vertically about one end will be (1) 200 J (2) 100 J (3) 50 J (4) 400 J 3. Work done by frictional force in pure rolling motion is (1) Positive (2) Negative (3) Positive or negative depends on the condition (4) Zero 4. A body of mass m tied to a string is moving in complete vertical circle. The difference in maximum and minimum tension in the string is (1) mg (2) 2mg (3) 3mg (4) 6mg 5. A bob of mass m is attached with a mass less string of length L as shown in figure. String is hung from a fixed point. Initial speed of ball is u = 2 gL . T ension in the string when it becomes horizontal is m u L (1) mg (2) 2 mg (3) Zero (4) 3 mg 6. The value of the coefficient of restitution for perfectly inelastic collision is (1) Equal to 1 (2) Greater than 1 (3) Zero (4) Less than 1 (2) 7. A ball of mass 3 kg is initially at rest. Due to explosion, it divides into two parts of 2 kg and 1 kg. If kinetic energy of heavier part is 8 J, then energy released in the explosion is (1) 16 J (2) 24 J (3) 20 J (4) 32 J 8. An automobile of mass m is accelerates from rest whose engine supplies a constant power P. The velocity attained after time t is proportional to (1) t 3/2 (2) t 1/2 (3) t (4) t 2 9. A ball is dropped from height 32 cm above ground level. If the coefficient of restitution between the ball and ground is 0.5 then, to what maximum height will it rise after first collision? (1) 16 m (2) 8 m (3) 4 m (4) 1 m 10. A wire of mass m and length l is bent in the form of an arc of a circle subtends an angle ? at its centre. Its moment of inertia (I) about an axis through centre of circle and normal to the plane of circle varies as (1) I ? ? (2) I ? ? –2 (3) (4) I ? ? 0 1 1. A disc is rolling without slipping on a horizontal smooth surface. Ratio of its translational kinetic energy to total kinetic energy is (1) (2) 5 3 (3) 3 2 (4) 7 5 12. A body is rolling down a rough inclined plane. Which force is responsible for increase in rotational kinetic energy? (1) Normal reaction by plane on body (2) Weight of the body (3) Frictional force (4) Gravitational force 13. The F - x graph of a particle of mass 1 kg is shown in the figure. If the particle begins to move from rest at x = 0, its velocity at x = 3 is O x F 10 N 3 m 6 m (1) (2) (3) (4) 14. Two springs having spring constants K 1 and K 2 are stretched by equal forces. The ratio of respective potential energies stored in them will be (1) 1 : 1 (2) K 1 : K 2 (3) K 2 : K 1 (4) : 15. A light ball is thrown with a speed of 5 m/s in a gravity free space and a very heavy lift is moving with a speed of 10 m/s as shown in the figure. If perfectly elastic collision takes place between the ball and floor of lift, then speed of the ball after collision (1) 15 m/s (2) 25 m/s (3) 5 m/s (4) 20 m/s 16. Three forces of equal magnitude F act on a moving body as shown. The body displaces by displacement S in a duration of t second. The kinetic energy of body increases by (assuming no other force or field) F F F S ? ? ? (1) 3FS (2) 2FS (3) FS (4) Zero 17. On a foggy day, drivers of two cars spot in front of each other when 70 m apart. They were travelling at 66 kmph and 60 kmph. Both apply brakes simultaneously which retard the cars at the rate of 5 m/s 2 each. Which of the following statements is correct? (1) The collision will be averted (2) The collision will take place (3) Their relative acceleration is zero (4) They will just collide 18. A uniform rod AB of length L and mass m is pivoted at end AB and is released from a horizontal position as shown in figure. Angular acceleration of rod about A at this instant is A B m, L (1) L g 2 (2) L g 2 3 (3) L g 3 (4) L g 3 2 (3) 19. If a conservative force is acting on a system, then work done by this force is equal to (1) Change in kinetic energy (2) Change in potential energy (3) Negative of charge in potential energy (4) Change in mechanical energy 20. In a head on inelastic collision of two balls travelling in same direction first ball stops after collision. If coefficient of restitution is 0.8 and velocities of balls before collision are 10 ms –1 and 5 ms –1 respectively then, the velocity of second ball after collision will be (1) 5 ms –1 (2) 8 ms –1 (3) 4 ms –1 (4) 12 ms –1 21. A ball of mass 500 g moving with speed 2 m/s collide to a horizontal floor making an angle of 45° with vertical. If coefficient of restitution is 1 3 , then the angle made by the ball with vertical, after collision is (1) 60° (2) 30° (3) 45° (4) 37° 22. A small block is released from point A as shown in the figure. It slides down the smooth surface AB and leaves contact with the surface at B horizontally. The horizontal range (R) of this block will be B H R m H/2 (1) (2) H (3) 4 H (4) 2 H 23. A very heavy block collides elastically to a very light stationary block on a smooth horizontal surface. After collision the velocity of light body will be (1) Zero (2) Same as the velocity of heavy block before collision (3) Twice of the velocity of heavy block before collision (4) Very high as compared to the velocity of heavy block before collision 24. Parallel axis and perpendicular axes theorems are respectively applicable for (1) Thin lamina only, thin lamina only (2) All bodies, thin lamina only (3) All bodies, all bodies (4) Thin lamina only, all bodies 25. Which of the following statement is incorrect? (1) If external torque on the system about an axis is zero, then the angular momentum about that axis is conserved (2) If external torque on the system about an axis is zero, then rotational kinetic energy about that axis is conserved (3) Any internal interaction between parts of the system cannot alter its total angular momentum (4) A particle moving parallel to x-axis or y-axis with constant velocity, then its angular momentum about origin will remain constant 26. A uniform rod AB of mass m and length 2a is falling freely without rotation under gravity with AB horizontal. Suddenly the end A is fixed when the speed of rod is v. The angular speed with which the rod begins to rotate is (1) 2 v a (2) (3) (4) 27. A disc and a ring of same mass and same radius are allowed for pure rolling on an rough inclined plane from same height. Ratio of their acceleration down the plane is (1) 4 : 3 (2) 3 : 4 (3) 5 : 2 (4) 2 : 5 28. A diver exhibits some rotations in air before touching the surface of water. In this case he uses the principle of (1) Conservations of linear momentum (2) Newton’s laws of motion (3) Conservation of angular momentum (4) Impulse momentum theorem 29. A body of mass 10 kg is dropped form rest from a height 20 m. If it reaches the ground with 10 m/s, then work done by air resistance is (1) + 1500 J (2) – 1500 J (3) + 500 J (4) – 500 J (4) 30. A body falling vertically downwards under gravity breaks in two parts of unequal masses. The centre of mass of the two parts taken together (1) Shifts horizontally towards heavier piece (2) Shifts horizontally towards lighter piece (3) Does not shift horizontally (4) Shifts vertically upward 31. Let F ext represents the sum of all external forces acting on the particles of the system. If F ext = 0, then which of the following is incorrect? (1) Acceleration of center of mass must be zero (2) Velocity of center of mass must be zero (3) Total momentum of system must be constant (4) Total kinetic energy of the system may change 32. Two bodies A and B have moment of interia I 1 and I 2 respectively . If both have same angular momenta, then their rotational kinetic energies are in the ratio (1) (2) (3) (4) 33. A body P moving with momentum collides with another body Q moving with momentum . After collision body P moves with momentum . Now momentum of body Q becomes (1) ˆ 6 j (2) (3) (4) 34. A string is wrapped around the circumference of a pulley of radius R. The moment of inertia of the pulley is I about horizontal axis. A weight Mg is attached to the end of the string and is released from rest. After falling through a distance H, the velocity of the wheel will be (1) (2) 1 2 2 2 2 ?? ?? ??? MgHR IMR (3) 1 2 2 2 4 ?? ?? ??? MgHR IMR (4) 1 2 2 2 2( ) ?? ?? ? ?? MgHR IMR 35. A thin rod of length L and mass m rotates with angular velocity ? in a horizontal plane about a vertical axis passing through its one end. Its rotational kinetic energy is (1) 22 1 24 mL ? (2) (3) (4) 36. A particle of mass 1 kg is moving in x-y plane with velocity m/s. The angular momentum of the particle about z-axis, when it is at a point (3, 4) m is (in SI units) (1) ˆ 25 k (2) – (3) (4) Zero 37. A force ˆ Fk ? acts at O, the origin of the coordinate system. The torque about the point (2, –2) is (1) (2) ) ˆ ˆ ( 2 j i F ? (3) ) ˆ ˆ ( 2 j i F ? ? (4) ) ˆ ˆ ( 2 j i F ? 38. Suppose that due to melting of the polar ice, the moment of inertia of the earth about its axis of rotation increases by 1%, then duration of the solar day will (1) Increase by 14.4 minute (2) Decrease by 14.4 minute (3) Increase by 14.4 second (4) Decrease by 14.4 second 39. A point object of mass m is kept at (a, 0). What mass should be kept at (–3a, 0), so that centre of mass lies at origin? (1) m (2) 2m (3) 3 m (4) 3m 40. A uniform circular disc of radius R has its centre at origin O as shown. If a circular groove of radius R/2 is made, the coordinates of the centre of mass of the remaining part is (1) ? ? ? ? ? ? 0 , 6 R (2) ? ? ? ? ? ? 6 , 0 R (3) ? ? ? ? ? ? 0 , 3 R (4) ? ? ? ? ? ? 3 , 0 R (5) 41. An uniform ring is released on a horizontal rough surface with horizontal velocity of centre of mass V 0 and angular velocity about centre of horizontal mass zero. The velocity of its centre of mass, when it starts pure rolling is (1) 2 0 V (2) 3 2 0 V (3) 5 3 0 V (4) 7 5 0 V 42. A man of mass 50 kg is standing on a horizontal planck of mass 150 kg placed on a horizontal frictionless plane. Initially both are at rest. If the man starts moving to right with speed 4 m/s w.r.t the planck, then the velocity of the planck is frictionless (1) 1 m/s to left (2) 1 m/s to right (3) 3 m/s to left (4) 3 m/s to right 43. Three identical thin rods each of mass m and length l are joined to form a letter H. The moment of inertia of the system about one of the sides of H is (1) 2 4 3 ml (2) 2 1 3 ml (3) 2 7 5 ml (4) 2 5 3 ml 44. A thin uniform rod of mass M and length L is inclined at an angle ? to OO' as shown in figure. The moment of inertia of the rod about the axis OO' is O O ? ? (1) 2 1 12 ML (2) 22 1 sin 3 ML ? (3) 22 1 cos 3 ML ? (4) ML 2 sin 2 ? 45. A thin uniform rod AB of mass M and length L is kept vertical on a rough horizontal plane. If it is allowed to fall without slipping at A, then its angular velocity just before hitting the ground is B M, L A (1) L g (2) L g 2 (3) L g 3 (4) L g 3 In the following questions (46 to 50), a statement of assertion (A) is followed by a statement of reason (R). (1) If both Assertion & Reason are true and the reason is the correct explanation of the assertion, then mark (1). (2) If both Assertion & Reason are true but the reason is not the correct explanation of the assertion, then mark (2). (3) If Assertion is true statement but Reason is false, then mark (3). (4) If both Assertion and Reason are false statements, then mark (4). 46. A : The change in kinetic energy of a body is equal to work done by only external forces acting on it. R : The internal forces acting on a system cannot change its kinetic energy. 47. A : A body with negative total energy can have momentum. R : Momentum cannot be negative. 48. A : The work done by centripetal force is always zero in a circular path. R : Centripetal force cannot change magnitude of velocity and hence kinetic energy remain constant. 49. A : If a body is in rotational equilibrium, then its angular momentum about any axis is conserved. R : If a body is in rotational equilibrium, then torque on its about any axis is zero. 50. A : Work done by friction force in pure rolling motion may be zero. R : The friction force acting in pure rolling motion of a rigid body is static friction.Read More

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