#### Kinematics - Important One Mark Question Paper

11th Standard

Reg.No. :
•
•
•
•
•
•

Physics

Time : 01:00:00 Hrs
Total Marks : 60

Part A

Multiple Choice Question

60 x 1 = 60
1. Which one of the following Cartesian coordinate systems is not followed in physics?

(a)

(b)

(c)

(d)

2. If a particle has negative velocity and negative acceleration, its speed

(a)

increases

(b)

decreases

(c)

remains same

(d)

zero

3. A ball is projected vertically upwards with a velocity v. It comes back to ground in time t. Which v-t graph shows the motion correctly?

(a)

(b)

(c)

(d)

4. If one object is dropped vertically downward and another object is thrown horizontally from the same height, then the ratio of vertical distance covered by both objects at any instant t is

(a)

1

(b)

2

(c)

4

(d)

0.5

5. Which one of the following satatement is true?

(a)

A scalar quantity is conserved in a process

(b)

A scalar quantity does not vary from one point to another in apace

(c)

A scalar quantity can never take -ve values

(d)

A scalar quantity has only magnitude and no direction.

6. The angle between A i +j and B = i - j is

(a)

45°

(b)

90°

(c)

-45°

(d)

180°

7. Distance is a scalar quantity and ______________ is a vector.

(a)

Speed

(b)

Length

(c)

Time

(d)

Displacement

8. The horizontal range of a projectile fired at an angle of 15° is 50 m. If it is fired with the same speed at angle of 45°, its range will be

(a)

125 m

(b)

75 m

(c)

100 m

(d)

150 m

9. Choose the motion in two dimension from the following.

(a)

Motion of a train along a straight railway track

(b)

An object falling freely under gravity close to the Earth.

(c)

A particle moving along a curved path in a plane.

(d)

Flying ofa kite on a windy day.

10. The sum of the magnitutes of two forces acting at a point is 16N. The resultant of these forces is perpendicular to the smaller forces and has a magnitude of 8 N. If the smaller forces of magnitude x, then the value of x is

(a)

2 N

(b)

4 N

(c)

6 N

(d)

7 N

11. The component of vector A=2i+3j along the vector i+j is

(a)

$\cfrac { 5 }{ \sqrt { 2 } }$

(b)

$10\sqrt { 2 }$

(c)

$5\sqrt { 2 }$

(d)

5

12. A and B are two vectors and $\theta$ is the angle between them,if $|A\times B|$=$\sqrt { 3 }$(A.B),the value of $\theta$ is

(a)

${ 60 }^{ 0 }$

(b)

${ 45 }^{ 0 }$

(c)

${ 30 }^{ 0 }$

(d)

${ 90 }^{ 0 }$

13. The value of n so that vectors 2i+3j-2k,5i+nj+k and -i+2j+3k may be coplanar,will be

(a)

18

(b)

28

(c)

9

(d)

36

14. Given A=4i+6j and B=2i+3j.Which of the following is correct?

(a)

$A\times B=0$

(b)

A.B=24

(c)

$\frac { |A| }{ |B| } =\frac { 1 }{ 2 }$

(d)

A and B are anti-parallel

15. A boat is sent across a river with a velocity of 8 km/h.If the resultant velocity of boat is 10 km/h,then velocity of river is

(a)

10 km/h

(b)

8 km/h

(c)

6 km/h

(d)

4 km/h

16. if $A.B=A\times B$,then the angle between A and B is

(a)

${ 45 }^{ 0}$

(b)

${ 30 }^{ 0 }$

(c)

${ 60 }^{ 0 }$

(d)

${ 90 }^{ 0 }$

17. If a vector 2i+3j+8k is perpendicular to the vector 4j-4i+$\alpha k$, then value of $\alpha$ is

(a)

-1

(b)

1/2

(c)

-1/2

(d)

1

18. If A=4i+4j+4k and B=3i+j+4k, then angle between vectors A and B is

(a)

${ 180 }^{ 0 }$

(b)

${ 90 }^{ 0 }$

(c)

${ 45 }^{ 0 }$

(d)

${ 0 }^{ 0 }$

19. Resultant of two vectors A and B is given by |R| = {|A|-|B|}, angle between A and B will be

(a)

90o

(b)

180o

(c)

0o

(d)

None of these

20. The resultant of A and B makes an angle $\alpha$ with A and $\beta$ with B, then

(a)

$\alpha < \beta$

(b)

$\alpha > \beta$ if A < B

(c)

$\alpha < \beta$ if A = B

(d)

$\alpha < \beta$ if A < B

21. At what angle should the two forces 2 P and $\sqrt2$P act so that the resultant force is P$\sqrt{10}$

(a)

45o

(b)

60o

(c)

90o

(d)

120o

22. Two vectors are such that |A + B| = |A - B|.  The angle between the vector is

(a)

0o

(b)

30o

(c)

60o

(d)

90o

23. If A and B are two non-zero vectors having equal magnitude, the angle between the vectors A and A - B is

(a)

0o

(b)

90o

(c)

180o

(d)

dependent on the orientation of A and B

24. For the resultance of two vectors to be maximum what must be the angle between them

(a)

0o

(b)

60o

(c)

90o

(d)

180o

25. Five equal forces of 10 N each are applied at one point and all are lying in one plane.  If the angles between them are equal, the resultance force will be

(a)

zero

(b)

10 N

(c)

20 N

(d)

10$\sqrt2$ N

26. Two vectors having equal magnitudes A make an angle $\theta$ with each other.  The magnitude and direction of the resultant are respectively

(a)

2A cos$\theta\over2$, along bisector

(b)

A cos $\theta\over2$, at 45o from one vector

(c)

2 A sin $\theta\over2$, along bisector

(d)

A cos$\theta\over2$,along bisector

27. The position vector of a moving particle at time t is r =  3 $\hat i$ - 4 t$\hat j$ - t$\hat k$.  Its displacement during the time interval t = 1 s to t = 3 s is

(a)

$\hat j \ - \ \hat k$

(b)

$3\hat i \ + \ 4\hat j \ - \ \hat k$

(c)

$9\hat i \ + \ 36\hat j \ - \ 27\hat k$

(d)

None of these

28. Resultant of which of  a following may be equal to zero?

(a)

10 N, 10 N, 10 N

(b)

10 N, 10 N, 25 N

(c)

10 N, 10 N, 35 N

(d)

None of these

29. Out of the following set of forces, the resultant of which cannot be zero

(a)

10, 10, 10

(b)

10, 10, 20

(c)

10, 20, 20

(d)

10, 20, 40

30. The angle between A + B and A - B will be

(a)

90o

(b)

between 0o and 180o

(c)

180o only

(d)

None of these

31. Velocity is said to be variable, if:

(a)

un equal displacement occur in equal intervals of time

(b)

direction of motion changes

(c)

both rate of motion and direction changes

(d)

all the above

32. Retardation means:

(a)

decreases with time

(b)

increases with time

(c)

increases and decreases

(d)

decreases and increases

33. Slope of displacement-time graph at any instant gives:

(a)

speed

(b)

acceleration

(c)

retardation

(d)

velocity

34. Slope of velocity-time graph at any instant gives:

(a)

speed

(b)

acceleration

(c)

retardation

(d)

velocity

35. The numerical ratio of average velocity to average speed is:

(a)

<1

(b)

=1

(c)

≤1

(d)

=0

36. If x=a cost is the displacement in time t then, acceleration is:

(a)

a cost

(b)

-a cost

(c)

a sint

(d)

-a sint

37. Choose the correct statement:

(a)

motion is an absolute term but rest is relative

(b)

motion is a relative term but rest is an absolute

(c)

both motion and rest are relative

(d)

both motion and rest are absolute

38. A passenger in the moving train tosses a coin. If the coin falls behind him, train must be moving with:

(a)

acceleration

(b)

deceleration

(c)

uniform speed

(d)

all the above

39. Apassenger in the moving train throws a coin. If the coin falls in front of him, train must be moving with:

(a)

uniform speed

(b)

acceleration

(c)

deceleration

(d)

uniform velocity

40. An object accelerates from rest at a constant rate 'a' for some time and afterwards, it decelerates at a constant, rate 'b' to come to rest If the total time elapsed is 't', the maximum velocity acquired by the object is

(a)

$abt\over(a+b)$

(b)

${(a+b)t\over ab}$

(c)

$t\over (a+b)$

(d)

$(a+b)t$

41. The distance covered by an object falling down freely under gravity in the last second of its motion is equal to the distance covered by it during the first five seconds of its motion. The time (in seconds) taken by the object to reach the ground is

(a)

8

(b)

5

(c)

13

(d)

10

42. The speed of a train is reduced from 60 kmh-1 to 15 kmh-1 in a distance of 450 m. If the retardation is uniform is the distance, it will travel further before coming to rest is

(a)

25m

(b)

30m

(c)

15m

(d)

20m

43. A stone projected vertically upwards with a speed of 15 ms-1 from the top of a tower strikes the base of the tower in 5s. The height of the tower is (g = 10 ms-2)

(a)

20m

(b)

45m

(c)

50m

(d)

35m

44. A lift, in which a boy is standing, moves upwards with a constant speed of 9.8 ms-1. If the boy drops a coin from a height of 2.5 m, the time taken by it to reach the floor of the lift is (g = 10 ms·-2)

(a)

$\sqrt{2s}$

(b)

${1\over \sqrt{3}}s$

(c)

$\sqrt{3s}$

(d)

${1\over\sqrt{2}}s$

45. An aeroplane moving horizontally with a speed of 180 kmhr-1 drops a food packet while flying at a height of
490 m. rille horizontal range of the food packet is

(a)

500m

(b)

200m

(c)

650m

(d)

925m

46. Preeti reached the metro station and found that the escalator was not working. She walked up the stationary escalator in time t1. On other days, if she remains stationary on the moving escalator, then the escalator takes her up in time f2• The time taken by her to walk upon the moving escalator will be

(a)

${t_1t_2\over t_2-t_1}$

(b)

${t_1t_2\over t_2+t_1}$

(c)

t1-t2

(d)

${ t_2+t_1\over 2}$

47. A car moves from X to Y with a uniform speed Vu and returns to Y with a uniform. speed vd The average speed for this round trip is

(a)

$\sqrt{v_uv_d}$

(b)

${v_dv_u\over v_d+v_u}$

(c)

${v_u+v_d\over 2}$

(d)

${2v_dv_u\over v_d+v_u}$

48. The position x of a particle with respect to time t along x-axis is given by x = 9t2 - t3 where x is in metres and in seconds. What will be the position of this particle when it achieves maximum speed along the +x direction?

(a)

54m

(b)

81m

(c)

24m

(d)

32m

49. Two bodies A (of mass 1 kg) and B (of mass 3 kg) are dropped from heights of 16 m and 25 m, respectively. The ratio of the time taken by them to reach the ground is

(a)

4/5

(b)

5/4

(c)

12/5

(d)

5/12

50. A ball is thrown vertically upward. It has a speed of 10 m/sec when it. has reached one half of its maximum height. How high does the ball rise?(Take g = 10 m/s2)

(a)

10m

(b)

5m

(c)

15m

(d)

20m

51. A particle is thrown vertically upward. Its velocity at half of the height is 10 m/s, then the maximum height attained by it (g = 10 m/s2)

(a)

8m

(b)

6m

(c)

10m

(d)

16m

52. Motion of a particle is given by equation s=(3t3+7t2+14t+8)m. The value of acceleration of the particle at t=1 sec is

(a)

10m/s2

(b)

32m/s2

(c)

23m/s2

(d)

16m/s2

53. If a car at rest accelerates uniformly to a speed of 144 krn/h in 20 sec, it covers a distance of

(a)

1440cm

(b)

2980cm

(c)

20m

(d)

400m

54. The acceleration of a particle is increasing linearly with time t as bt, The particle starts from origin with an initial velocity vo. The distance travelled by the particle in time t will be

(a)

$v_ot+{1\over 3}bt^2$

(b)

$v_ot+{1\over 2}bt^2$

(c)

$v_ot+{1\over 6}bt^2$

(d)

$v_ot+{1\over 3}bt^3$

55. The water drop falls at regular intervals from a tap 5 m above the ground. The third drop is leaving the tap at instant the first drop touches the ground. How far above the ground is the second drop at that instant?

(a)

3.75m

(b)

4.00m

(c)

1.25m

(d)

2.50m

56. The velocity of train increases uniformly from 2o km/h to 60 km/h in 4 hours. The distance travelled by the train during this period is

(a)

160km

(b)

180km

(c)

100km

(d)

120km

57. The radius of the earth was measured by

(a)

Newton

(b)

Eratosthenes

(c)

Galileo

(d)

Ptolemy

58. The branch of mechanics which deals with the motion of objects without taking force into account is

(a)

kinetics

(b)

dynamics

(c)

kinematics

(d)

statics

59. If the coordinate axes (x, y, z) are drawn in anticlockwise direction then the co-ordinate system is known as

(a)

Cartesian coordinate system

(b)

right-handed coordinate system

(c)

left-handed coordinate system

(d)

cylindrical coordinate system

60. Spreading smoke of incense stick is an example of

(a)

one dimensional motion

(b)

two dimensional motion

(c)

three dimensional motion

(d)

none