Shashi

Brilliant Exam Engine Answer Key with Hint Total time :40 Min Maximum mark: 120 Subject :Demo Test Mark for True answer: 4 Chapter :One Dimensional Motion Mark for Wrong Answer: -1 1. A particle starts from the origin, goes along x-axis to the point (20m, 0) and then returns along the same line to the point (-20m, 0). The distance and displacement of the particle during the trip are A)40m, 0 B)40m, 20m C)40m, -20 m D)60m, -20 m E)+20m, -40 m Hint: Distance = 20 + [20 – (-20)] = 60 m Displacement = -20 – 0 = -20 m 2.Choose the correct statement from the following A)The magnitude of velocity of a particle is equal to its speed B)The magnitude of the average velocity in an interval is equal to its average speed in that interval C)It is impossible to have a situation in which the speed of the particle is never zero but the average speed in an interval is zero D)It is possible to have a situation in which the speed of particle is zero but the average speed is not zero E)Both A and B 3.Which of the following is not an example of linear motion A)A book at rest B)A body in uniform circular motion C)Wheel rotating at uniform speed on road D)A body rolling down an inclined plane E)None 4. The correct statement from the following is A)A body having zero velocity will not necessarily have zero acceleration B)A body having zero velocity will necessarily have zero acceleration C)A body having uniform speed can have only uniform acceleration D)A body having non-uniform velocity will have zero acceleration E)All the above 5.When two bodies move uniformly towards each other the distance between them decreases by 8 m/s. If both bodies move in the same direction with different speeds the distance between them increases by 2 m/s. The speeds of two bodies will be A)4 m/s and 3 m/s B)4 m/s and 2 m/s C)5 m/s and 3 m/s D)7 m/s and 3m/s E)8 m/s and 4 m/s Hint: 6. A car runs at a constant speed on a circular track of radius 100m, taking 62. 8 sec on each lap. What is avera ge velocity and average speed on each lap A)10m/s, 10 m/s B)0, 0 C)0, 10 m/s D)10 m/s, 0 m/s E)10m/s, 5 m/s Hint: . Distance travelled by a body is directly proportional to time, then the speed of the body A)increases B)decreases C)first increases and then decreases D)is zero E)remains the same 8. A car moving with a speed of 40 km/h can be stopped by applying breaks after at least 2m. If the same car is moving with a speed of 80 km/h, the minimum stopping distance is A)8 m B)2 m C)4 m D)6 m E)10 m Hint: A)Acceleration B)Velocity C)Displacement D)Distance E)Mass 9. 10.The distance travelled by a body falling freely from rest in first, second and third seconds are in the ratio A)1 : 2 : 3 B)1 : 3 : 5 C)1 : 4 : 9 D)1 : 4 : 5 E)1 : 1 : 1 Hint: A)6 sec B)8 sec C)10 sec D)4 sec E)Cannot catch the bus 11. Hint: 12. A)Uniform acceleration B)Uniform retardation C)Non-uniform acceleration D)Zero acceleration E)Non-uniform retardation Hint: 13. A)Directly towards the target B)5 cm above the t arget C)10 cm above the target D)15 cm above the target E)5 cm below the target Hint: A B C D E 14. Hint: 15.With doubling the speed of a vehicle the distance required to stop it becomes A)Doubled B)Halved C)Tripled D)Four times E)Five times Hint: A B C D 16. E 17. A B C D E 18. A B C D E 19. A B C D E 20. If displacement of a particle is zero, distance covered by it A)may be zero or may not be zero B)must be zero C)must not be zero D)all are true E)all are false 21. The distance travelled is given by A)area under speed – time graph B)area under distance – time graph C)slope of velocity – time graph D)slope of velocity – time graph E)None 22. A B C D E Hint: 23.A ball is thrown upward. After it has left the hand, its acceleration A)decreases B)increases C)is zero D)remains constant E)will increase during descending and decrease during ascending 24. A)20 m B)25 m C)30 m D)45 m E)40 m Hint: A B C D E 25. Hint: 26. A body is thrown upwards and reaches its ma ximum height. At that position A)its acceleration is minimum B)its velocity is zero and acceleration is also zero C)its velocity is zero but acceleration is maximum D)its velocity is zero and its acceleration is the acceleration due to gravity E)both A and B 27.A)Velocity – displacement relation B)Position – time relation C)Time – Velocity relation D)Time – displacement relation E)Acceleration displacement relation 28. A)Velocity B)Acceleration C)Displacement D)Speed E)A and B 29. Speed is a: A)vector quantity B)scalar quantity C)neither vector nor scalar D)sometimes vector sometimes scalar E)none 30. A particle moves with uniform velocity. Which of the following statements is true: A)Its speed is zero B)its acceleration is zero C)its speed is variable D)its acceleration is opposite to velocity E)its velocity is negative