Tiêu đề 04. MOTION IN A PLANE.pdf ✅

PAPER 1 (1.) A mass of 2 kg is whirled in a horizontal circle by means of a string at an initial speed of 5 revolutions per minute. Keeping the radius constant the tension in the string is doubled. The new speed is nearly : (1) 14rpm (2) 10rpm (3) 2.25rpm (4) 7rpm (2.) If a body is moving in a circle of radius r metres with a constant speed v metre/ sec. The angular velocity is : (1) r v/ (2) vr (3) 2 v r/ (4) v r/ (3.) The ratio of magnitudes of angular velocity of the hour hand of a watch to that of earth's rotation about its own axis is : (1) 1:1 (2) 1: 2 (3) 1:3 (4) 2:1 (4.) When a particle moves along a curved path then its velocity is : (1) Tangential to its path (2) Normal to its path (3) Constant (4) None of the above is true (5.) A body of mass m is moving in a circle of radius r with a constant speed v . The force on the body is 2 mv r and is directed towards the centre. What is the work done by this force in moving the body over half the circumference of the circle : (1) 2 mv r r  (2) Zero (3) 2 2 mv r (4) 2 2 r mv  (6.) What is constant for a body moving in a horizontal circle with a uniform angular speed : (1) Velocity (2) Acceleration (3) Force (4) Kinetic energy (7.) A cyclist moves around a circular path of radius 39.2 m with a speed of 1 19.6 ms− . He must lean inwards at an angle  with vertical given by : (1) 1  tan 1− = (2) 1  tan 2 − = (3) 1  tan 3 − = (4) 1  tan 4 − = (8.) A stone tied to the end of a 20 cm long string is whirled in a horizontal circle. If the centrpetal acceleration is 2 9.8 ms− , its angular speed in radian/ sec is : (1) 7 (2) 14 (3) 49 (4) 98 (9.) A particel makes ' f ' revolutions per sec in a circular path of radius r . Its centripetal acceleration is : (1) 2 2 4 f r (2) 2 4 f r (3) 2 2 4 f r (4) 2 2 2 4 f r 
JOIN US NEET TEST PAPERS TO GET FULL PAPERS INCLUDE SCORE BOOSTER, RANK BOOSTER QUESTIONS PURELY NCERT BASED, INCLUDES PAGE NUMBER CHAPTER WISE CLICK HERE OR
(10.) A particle is moving in circle of radius r centered at O with constant speed v . The change in velocity in moving from A to B( AOB 40 = ) is : (1) 2 cos40 v (2) 2vsin40 (3) 2vcos20 (4) 2vsin20 (11.) A particle moves in a circle of radius 25 cm at two revolutions per second. The acceleration of the particle in metre per seond 2 is (1)  (2) 2 8 (3) 2 2 (4) 2 4 (12.) A bucket tied at the end of a 1.6 m long string is whirled in a vertical circle with constant speed. what should be the minimum speed so that water from the bucket does not spill when the bucket is at the hightest position? (take 2 g 10 ms− = ) : (1) 4 m / sec . (2) 6.25 m / sec (3) 16 m / s (4) None of these (13.) Find the maximum velocity with which a train can be moved on a circular track of radius 200 m . the banking of the track is 5.71 and tan5.17 0.1 = : ( ) 2 g = 9.8 m / s (1) 1 1.4 ms− (2) 1 14 ms− (3) 1 140 ms− (4) 1 0.14 ms− (14.) Two particles of equal masses are revolving in circular paths of radii 1 r and 2 r respectively with the same speed. The ratio of their centripetal force is : (1) 2 1 r r (2) 2 1 r r (3) 2 1 2 r r       (4) 2 2 1 r r       (15.) A mass of 100gm is tied to one end of a string 2 m long. The body is revoling in a horizontal circle making a maximum of 200 revolutions per min. The other end of the string is fixed at the centre of the circle of revolution. The maximum tension in the string is. [approximately] (1) 8.76 N (2) 8.94 N (3) 89.42 N (4) 87.64 N (16.) In a vertical circle of radius r , at what point in its path a particle has tension equal to zero (when particle just complete the circle) : (1) Highest point (2) Lowest point
(3) Any point (4) At a point horizontally from the centre of circle of radius r . (17.) The tension in the string revolving in a vertical circle with a mass m at the end when it is at the lowest position. (1) 2 mv r (2) 2 mv mg r − (3) 2 mv mg r + (4) mg (18.) The angular speed of a fly wheel making 120 revolutions/minute is. (1) 2 rad / s  (2) 2 4 rad / s  (3) rad / s (4) 4 rad / s  (19.) A cane filled with water is revolved in a vertical circle of radius 4 meter and the water just does not fall down. The approximate time period of revolution will be ( ) 2 g =10 m / s : (1) 1sec (2) 10sec (3) 8sec (4) 4sec (20.) A particle of mass m is executing uniform circular motion on a path of radius r . If p is the magnitude of its linear momentum. The radial force acting on the particle is (1) pmr pmr (2) rm p (3) 2 mp r (4) 2 p rm (21.) The average acceleration vector for a particle having a uniform circulur motion is (1) A constant vector of magnitude 2 n / r (2) A vector of magnitude 2 n r/ directed normal to the plane of the given uniform circular motion. (3) Equal to the instantaneous acceleration vector at the start of the motion. (4) A null vector. (22.) A motor cyclist moving with a velocity of 72 km / hour on a flat road takes a turn on the road at a point where the radius of curvature of the road is 20 meters. The acceleration due to gravity is 10 m / 2 sec . In order to avoid skidding, he must not bend with respect to the vertical plane by an angle greater than- (1) 1  tan 6 − = (2) 1  tan 2 − = (3) 1  tan 25.92 − = (4) 1  tan 4 − = (23.) A motorcycle is going on an overbridge of radius R. The driver maintains a constant speed. As the motorcycle is ascending on the overbridge, the normal force on it. (1) Increases (2) Decreases (3) Remains the same (4) Fluctuates