Karnataka Examination Authority. CET - Coaching Program - Physics

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1 Karnataka Examination Authority CET - Coaching Program - Physics Topics covered: Vectors, Motion in Two and Three Dimension, Friction, Statics 1) If the resultant of the vectors ( ), ( - + ) and is a unit vector along the y- direction, then is ) If the vectors = + 4 and = 5 + p are parallel to each other, the magnitude of is ) If = and If = + 5 and If = X, then the vector makes an angle of with X axis with Y axis with Z axis with Z axis 4) If the scalar and vector products of two vectors, are equal in magnitude, then the angle between the two vectors is ) A body is projected horizontally with speed 0 m/s from top of a tower. What will be its speed at time 5 s after projection? Take g = 10 m/s m/s. 0 m/s m/s m/s

2 6) In a projectile motion, the velocity 1. Is never perpendicular to the acceleration. Is always perpendicular to the acceleration 3. Is perpendicular to acceleration at one instant only 4. Is perpendicular to acceleration at two instants 7) A body is projected at an angle of 30 0 to the horizontal with kinetic energy E. The K.E., at the topmost point is 1. Zero. E/4 3. E/ 4. 3E/4 8) A particle has an initial velocity of and an acceleration of Its speed after 10 s is units. 8.5 units 3. 7 units 4. 7 units 9) For a given angle of projection, if the time of flight of a projectile is doubled, the horizontal range will increase to 1. Four times. Thrice 3. Once 4. Twice 10) A particle is projected at 60 0 to the horizontal with an energy E. The kinetic energy and potential energy at the highest point are 1. (E/, E/)., 3. (E,0) 4., 11) A number of bullets are fired in all possible directions with same initial velocity u the maximum area at the ground covered by the bullets is

3 1. u π 3. π g u g. u u π g 4. π g 1) A motor boat covers the distance between the two localities on a river in 6 hours downstream and in 8 hours upstream. The speed of the boat is how many times that of the river? 1. 5 times. 8 times 3. 7 times 4. 6 times 13) Two bodies of equal masses revolve in circular orbits of radii R 1 and R with the same period. Their centripetal forces are in the ratio ) If the radius of the circular path of particle going around the circle is doubled without changing its frequency of rotation, then centripetal force on it is 1. Unchanged. Doubled 3. Halved 4. Quadrupled 15) A particle is moving along a circular path with a uniform speed. How does its angular velocity change when it completes half of the circular path? 1. No change. Increases 3. Decreases 4. Cannot say 16) A curved road of diameter 1.8 km is banked so that no friction is required at a speed of 30 m/s. What is the banking angle?

4 ) A Block of mass m is placed on a smooth inclined plane of inclination θ with the horizontal. The force exerted by the plane on the block has a magnitude 1. mg. mg/cosθ 3. mgcosθ 4. mg tanθ 18) The coefficient of friction between two surfaces is 0. The angle of friction is 1. sin -1 (0.). cos -1 (0.) 3. tan -1 (0.1) 4. cot -1 (5) 19) Block A of mass 35 kg is resting on frictionless floor. Another block B of mass 7 kg is resting on it as shown in the figure. The coefficient of static friction between the blocks is 0.5 while coefficient of kinetic friction is 0.4. If a force 100 N is applied to the block B acceleration of block A will be (g=10ms - ) ms -..4 ms ms ms -

5 0) Two forces F and F all at an angle θ. When the first force is doubled and second force is increased by 0 N, the direction of resultant remain unchanged. The value of F is 1. 10N. 0N 3. 5N 4. 35N 1) A 5 kg picture is supported by two strings that run from its upper corners to a nail on the wall each string makes 60 0 angle with the vertical. The tension in each of the string is kg weight. 3.9 kg weight 3. 5 kg weight kg weight ) A balance is made of a rigid rod free to rotate about a point not at the center of the rod. When an unknown mass m is placed on the left pan, it is balanced by a mass m 1 placed in the right pan. And similarly when a mass m is placed in the right pan, it is balanced by a mass m in the left pan. Neglecting the mass of pans, m is 1 1. ( m + m ) 1. m m m + m 4. m + 1 m 3) Out of the following pairs of forces, the resultant of which can not be 4 N? 1. N and N. N and 4N 3. N and 6N 4. N and 8N

6 4) Iff = + and a magnitud des of If en and angle betwee 1. Sin-1 (3/4) ( -1. Cos (4/5) 3. Tan-1 (5/3) 4. Cos-1 (3/5), and are e 5, 4 and 3 units u respecctively, then iss T co-ordina ates of a mo oving particle e at time t arre give by x= =ct and y = bt. The 5) The in nstantaneous s speed of th he particle iss 1. t (b + c). t (b + c)1/ 3. t (c + b) 4. t (c + b)1/ d by two cab bles as show wn in the Figure. Then th he ratio of 6) A man 80 kg is supported te ensions T1 and T is 1. 1 : 1. 1 : 3. : : 3

7 7) Three forces of magnitudes 6 N, 6 N and N act as a corner of a cube along three sides as shown in figure. Resultant of these forces is 1. 1 N angle OB. 18 N along OA N along OC 4. 1 N along OE 8) Given = X and = X, what is the angle between and? 9) Two projectiles, A and B are projected with angle of projection 30 0 for the projectile A and 45 0 for the projectile B. If R A and R B are the horizontal ranges for the two projectiles, then 1. R A = R B. R A > R B 3. R A < R B 4. The information is insufficient to decide the relation of R A and R B. 30) A man can throw a stone to a maximum distance of 80 meters. The maximum height to which it will rise in meters is m. 0 m m m

8 31) Ratio of minimum kinetic energies of two projectiles of same mass is 4:1. The ratio of the maximum height attained by them is also 4:1. The ratio of their ranges would be 1. :1. 4:1 3. 8: :1 3) The projectiles are fired at different angles with the same magnitude of velocity, such that they have the same range. At what angles they might have been projected? and and and and ) A body is thrown upwards from the earth surface with velocity 5 ms -1 and from a planet surface with velocity 3 ms -1. Both follow the same path. What is the projectile acceleration due to gravity of the planet? Acceleration due to gravity on earth is 10 ms ms ms ms ms - 34) An aeroplane flies in a horizontal circle of radius 3.06 km at a speed of 150 m/s. The direction of the resultant force on air craft is: with the vertical with the vertical with the vertical with the vertical 35) A can filled with water is revolved in vertical circle of radius 4 m and the water just does not fall down. The time period of revolution will be 1. 1 s. 10 s 3. 8 s 4. 4 s 36) A particle of mass kg is moving along a circular path of radius 1 m. If its angular speed is π rad s -1, the centripetal force will be 1. 4πN

9 . 4π N 3. 8πN 4. 8π N 37) A stone of mass m is tied to a string of length l and rotated in a circle with a constant speed v. If the string is released, the stone flies: 1. Radially outwards. Radially inwards 3. Tangentially 4. With an acceleration of mv /l 38) A particle covers equal distance around a circular path, in equal intervals of time. Which of the following quantity connected with the motion of the particle remains constant with time? 1. Velocity. Acceleration 3. Speed 4. Displacement 39) The angle which the bicycle and its rider must make with the vertical when going round a curve of 7 m radius at 5 m/s is A mass of 10kg is suspended from a spring balance. It is pulled by a horizontal force so that the spring balance makes an angle 30 0 with the vertical. The reading of the spring balance in kg wt is 1) 5 ) 10 3) ) A heavy iron bar of weight W is having its one end on the ground and the other on the shoulder of a man. The bar makes an angle θ with the horizontal the weight experienced by the man is 1) W cos θ ) W sin θ 3) W 4) W

10 4. The resultant of two unlike parallel forces is 1N at a distance of 1 m from the greater force and on the same side as the greater force. The lines of action of the forces are separated by 0. m. The forces are 1) 5N and 6N ) 3N and 4N 3).5 N and 3.5 N 4) 15 N and 16 N 43. A wide gate at a compound can be opened with minimum effort (applied force) by holding the gate 1) at its centre ) nearer to hinged end ) at the farthest end from the hinged end 4) anywhere 44. If R is the range of a projectile angle of projection of 15 0 with horizontal, then the other angle of projection for which range R, is 1) 75 0 ) ) ) A body is projected at an angle 30 0 with the horizontal with momentum p. At its highest point the momentum is p 1) p ) 3 3) p 4) p A man can throw a ball to a maximum range of 50 m. How high can he throw the same ball 1) 50m )100m 3)0m 4)5m 47. An athlete executing long jump leaves the ground at a 30 0 angle and travels 8.90m. The take off speed at athlete is 1) 7.0ms -1 ) 8.0ms -1 3) 9.0ms -1 4)10.0ms A body is projected at such an angle that the horizontal range is three times the greatest height the angle at projection is 1) ) ) ) Two bullets are fired horizontally with different velocities from same height which will reach the ground first 1) slower one ) faster one 3)both reach simultaneously 4) It cant be predicted

11 50. Two projectiles are projected with same velocity. If one projected at an angle of 30 0 and other is 60 0 to the horizontal. The ratio of maximum height attained is 1) 3:1 ) 1:3 3)1: 4):1 51. There is two values of time for which a projective is at the same height. The sum of these two times is 3T 4T 3T 1) ) 3) 4) T The speed at the projectile is reduces by 50% on reaching the maximum height. The range on the horizontal plane is u u 3u 3u 1) ) 3) 4) 3g g g g 53. An electron is revolving around a nucleus at a distance of 0.58A 0 with velocity.18x10 6 ms -1. The acceleration of the electron is 1) zero ) 9X10 ms - 3) 10 0 ms - 4) 7.6X10 1 ms A body executing uniform circular motion in a circle at radius r Choose the correct statement 1)velocity of the body constant )acceleration of the body is constant 3)speed of the body is constant 4)angular velocity is zero 55. A block of mass 1kg slides down on a rough inclined plane of inclination 60 0 starting from its top. If the coefficient of kinetic friction is 0.5 and the length of the plane is 1m, then the work done against friction is (g=9.8 ms - ) 1) 9.8 J ) 4.94 J 3).45 J 4) 0 J 56. A body of mass 100g is sliding on an inclined plane of inclination The frictional force experienced ( if µ =1/1.73 and g=10 ms - ) is 1) 3 N )3 N 3)1.5 N 4) 0.5 N 57. A 10 kg box is placed on a surface. Coefficient of friction between the surface and the box is µ = 0.5. If a horizontal force of 100 N is applied, then the acceleration of the block will be (g=10 ms - ) 1).5 ms - ) 5 ms - 3) 7.5 ms - 4) zero

12 58. If the normal reaction is doubled coefficient of friction is 1) doubled ) halved 3) not changed 4) quadrupled 59. A mass m slides from rest down the surface at a frictionless hemispherical bowl of radius r from the highest point A as shown in the figure. The velocity of the mass m when it reaches ground is 1) gr ) mgr 3) mgr 4) gr 60. A bucket filled with water is revolved in a circle of radius 4m. if g=10ms -. The time period of revolution nearly equal to 1). 4 s )5 s 3) 8 s 4)10 s K L Ramachandra Murthy Faculty, Learning P U College Vijayanagar I Stage, Mysore Ph: