# MCQ Questions Chapter 3 Motion in a Straight Line Class 11 Physics

Please refer to MCQ Questions Chapter 3 Motion in a Straight Line Class 11 Physics with answers provided below. These multiple-choice questions have been developed based on the latest NCERT book for class 11 Physics issued for the current academic year. We have provided MCQ Questions for Class 11 Physics for all chapters on our website. Students should learn the objective based questions for Chapter 3 Motion in a Straight Line in Class 11 Physics provided below to get more marks in exams.

## Chapter 3 Motion in a Straight Line MCQ Questions

Please refer to the following Chapter 3 Motion in a Straight Line MCQ Questions Class 11 Physics with solutions for all important topics in the chapter.

MCQ Questions Answers for Chapter 3 Motion in a Straight Line Class 11 Physics

Question. The study of motion, without consideration of its cause is studied in
(a) statistics
(b) kinematics
(c) mechanics
(d) modern physics

B

Question. A particle experiences constant acceleration for 20 seconds after starting from rest. If it travels a distance s1 in the first 10 seconds and distance s2 in the next 10 seconds, then
(a) s2 = s1
(b) s2 = 2 s1
(c) s2 = 3 s1
(d) s2 = 4 s1

C

Question. A train of 150 m length is going towards north direction at a speed of 10 ms–1. A parrot flies at a speed of 5 ms–1 towards south direction parallel to the railway track. The time taken by the parrot to cross the train is equal to
(a) 12 s
(b) 8 s
(c) 15 s
(d) 10 s

D

Question. The ratio of the numerical values of the average velocity and average speed of a body is always:
(a) unity
(b) unity or less
(c) unity or more
(d) less than unity

B

Question. Which of the following changes when a particle is moving with uniform velocity?
(a) Speed
(b) Velocity
(c) Acceleration
(d) Position vector

D

Question. If the displacement of a particle varies with time as √x = t + 7 , the
(a) velocity of the particle is inversely proportional to t
(b) velocity of the particle is proportional to t
(c) velocity of the particle is proportional to √t
(d) the particle moves with a constant acceleration

B

Question. The initial velocity of a particle is u (at t = 0) and the acceleration a is given by f t. Which of the following relation is valid?
(a) v = u + f t2
(b) v = u + f t2/2
(c) v = u + f t
(d) v = u

B

Question. A particle has moved from one position to another position
(a) its distance is zero
(b) its displacement is zero
(c) neither distance nor displacement is zero
(d) average velocity is zero

C

Question. The displacement of a body is zero. The distance covered
(a) is zero
(b) is not zero
(c) may or may not be zero
(d) depends upon the acceleration

C

Question. The displacement x of a particle moving along a straight line at time t is given by x = a0 + a1 t + a2 t2 What is the acceleration of the particle
(a) a1
(b) a2
(c) 2 a2
(d) 3 a2

C

Question. The slope of the velocity time graph for retarded motion is
(a) positive
(b) negative
(c) zero
(d) can be +ve, –ve or zero

B

Question. The area of the acceleration-displacement curve of a body gives
(a) impulse
(b) change in momentum per unit mass
(c) change in KE per unit mass
(d) total change in energy

C

Question. The displacement-time graphs of two particles A and B are straight lines making angles of respectively 30º and 60º with the time axis. If the velocity of A is vA and that of B is vB, the value of vA/vB is
(a) 1/2
(b) 1/√3
(c) √3
(d) 1/3

D

Question. The distance through which a body falls in the nth second is h. The distance through which it falls in the next second is
(a) h
(b) h + (g/2)
(c) h – g
(d) h + g

D

Question. Figure shows the v-t graph for two particles P and Q. Which of the following statements regarding their relative motion is true ? Their relative velocity is
(a) is zero
(b) is non-zero but constant
(c) continuously decreases
(d) continuously increases

D

Question. A stone is dropped into a well in which the level of water is h below the top of the well. If v is velocity of sound, the time T after which the splash is heard is given by

B

Question. A person travels along a straight road for the first half time with a velocity v1 and the second half time with a velocity v2. Then the mean velocity v is given by

A

Question. It is given that t = px2 + qx, where x is displacement and t is time. The acceleration of particle at origin is

A

Question. A particle covers half of the circle of radius r. Then the displacement and distance of the particle are respectively
(a) 2πr, 0
(b) 2r, πr
(c) (πr/2) 2r
(d) πr, r

B

Question. The deceleration experienced by a moving motorboat after its engine is cut off, is given by dv/dt = – kv3 where k is constant. If v0 is the magnitude of the velocity at cut-off, the magnitude of the velocity at a time t after the cut-off is

A

Question. The displacement of a particle is given by√ x = t +1. Which of the following statements about its velocity is true ?
(a) It is zero
(b) It is constant but not zero
(c) It increases with time
(d) It decreases with time

C

Question. Two cars A and B are travelling in the same direction with velocities vA and vB (vA>vB). When the car A is at a distance d behind the car B the driver of the car A applies brakes producing a uniform retardation a. There will be no collision when

C

Question. A body is thrown upwards and reaches its maximum height. At that position
(a) its acceleration is minimum
(b) its velocity is zero and its acceleration is also zero
(c) its velocity is zero but its acceleration is maximum
(d) its velocity is zero and its acceleration is the acceleration due to gravity

D

Question. The position x of a particle varies with time (t) as x = A t2 – B t3. The acceleration at time t of the particle will be equal to zero. What is the value of t?
(a) 2A/3B
(b) A/B
(c) A/3B
(d) zero

C

Question. A point traversed half of the distance with a velocity v0. The half of remaining part of the distance was covered with velocity v1 & second half of remaining part by v2 velocity. The mean velocity of the point, averaged over the whole  time of motion is

D

Question. The acceleration of a particle is increasing linearly with time t as bt. The particle starts from the origin with an initial velocity v0. The distance travelled by the particle in time t will be

C

Question. The acceleration of a particle, starting from rest, varies with time according to the relation a = -sϖ2 sinwt The displacement of this particle at a time t will be
(
a) s sin ϖ t
(b) s ϖ cos ϖ t
(c) s w sin ϖ t
(d) – (1/2) (s ϖ2 sin ϖt) t2

A

Question. Two bodies of masses m1 and m2 fall from heights h1 and h2 respectively. The ratio of their velocities, when they hit the ground is

B

Question. The displacement of a particle is given by y = a + b t + c t2 – d t4 The initial velocity and acceleration are respectively
(a) b, – 4 d
(b) – b, 2 c
(c) b, 2 c
(d) 2 c, – 4 d

C

Question. A bus starts moving with acceleration 2 m/s2. A cyclist 96 m behind the bus starts simultaneously towards the bus at 20 m/s. After what time will he be able to overtake the bus?
(a) 4 sec
(b) 8 sec
(c) 12 sec
(d) 16 sec

B

Question. The two ends of a train moving with constant acceleration pass a certain point with velocities u and v. The velocity with which the middle point of the train passes the same point is
(a) (u + v)/2
(b) (u2 + v2)/2

C

Question. A passenger travels along the straight road for half the distance with velocity v1 and the remaining half distance with velocity v2. Then average velocity is given by
(a) v1v2
(b) v2 2/ v12
(c) (v1 + v2 )/2
(d) 2v1v2 / (v1 + v2)

D

Question. A point moves with uniform acceleration and v1, v2 and v3 denote the average velocities in t1, t2 and t3 sec. Which of the following relation is correct?
(a) (v1 – v2 ):(v2 – v3 ) = (t1 – t 2 ): (t 2 + t 3 )
(b) (v1 – v2 ):(v2 – v3 ) = (t1 + t 2 ): (t 2 + t3 )
(c) (v1 – v2 ):(v2 – v3) = (t1 – t2 ): (t1 – t3)
(d) (v1 – v2 ):(v2 – v3 ) = (t1 – t2 ): (t 2 – t3 )

B

Question. A particle accelerates from rest at a constant rate for some time and attains a velocity of 8 m/sec. Afterwards it decelerates with the constant rate and comes to rest. If the total time taken is 4 sec, the distance travelled is
(a) 32 m
(b) 16 m
(c) 4 m
(d) None of the above

B

Question. The velocity of a particle at an instant is 10 m/s. After 5 sec, the velocity of the particle is 20 m/s. Find the velocity at 3 seconds before from the instant when velocity of a particle is 10m/s.
(a) 8 m/s
(b) 4 m/s
(c) 6 m/s
(d) 7 m/s

B

Question. A particle is moving along a straight line path according to the relation s2 = at2 + 2bt + c s represents the distance travelled in t seconds and a, b, c are constants. Then the acceleration of the particle varies as
(a) s–3
(b) s3/2
(c) s–2/3
(d) s2

A

Question. When the speed of a car is v, the minimum distance over which it can be stopped is s. If the speed becomes n v, what will be the minimum distance over which it can be stopped during same retardation
(a) s/n
(b) n s
(c) s/n2
(d) n2 s

D

Question. A stone thrown vertically upwards with a speed of 5 m/sec attains a height H1. Another stone thrown upwards from the same point with a speed of 10 m/sec attains a height H2. The correct relation between H1 and H2 is
(a) H2 = 4H1
(b) H2 = 3H1
(c) H1 =2H2
(d) H1 = H2

A

Question. A stone is thrown vertically upwards. When the particle is at a height half of its maximum height, its speed is 10m/sec, then maximum height attained by particle is (g = 10m/sec2)
(a) 8 m
(b) 10 m
(c) 15 m
(d) 20 m

B

Question. From a 10m high building a stone ‘A’ is dropped & simultaneously another stone ‘B’ is thrown horizontally with an initial speed of 5 m/sec–1. Which one of the following statements is true?
(a) It is not possible to calculate which one of two stones will reach ground first
(b) Both stones ‘A’ & ‘B’ will reach the ground simultaneously.
(c) ‘A’ stones reach the ground earlier than ‘B’
(d) ‘B’ stones reach the ground earlier than ‘A’

B

Question. A body covers 26, 28, 30, 32 meters in 10th, 11th, 12th and 13th seconds respectively. The body starts
(a) from rest and moves with uniform velocity
(b) from rest and moves with uniform acceleration
(c) with an initial velocity and moves with uniform acceleration
(d) with an initial velocity and moves with uniform velocity

C

Question. A ball is dropped downwards, after 1 sec another ball is dropped downwards from the same point. What is the distance between them after 3 sec?
(a) 25 m
(b) 20 m
(c) 50 m
(d) 9.8 m

A

Question. Two trains are each 50 m long moving parallel towards each other at speeds 10 m/s and 15 m/s respectively. After what time will they pass each other?
(a) √5 2/3 sec
(b) 4 sec
(c) 2 sec
(d) 6 sec

B

Question. The relative velocity VAB or VBA of two bodies A & B may be
(1) greater than velocity of body A
(2) greater than velocity of body B
(3) less than the velocity of body A
(4) less than the velocity of body B
(a) (1) and (2) only
(b) (3) and (4) only
(c) (1), (2) and (3) only
(d) (1), (2), (3) and (4)

D

Question. A ball is projected vertically upwards with kinetic energy E. The kinetic energy of the ball at the highest point of its flight will be
(a) E
(b) E /√2
(c) E/2
(d) zero

D

Question. A stone thrown upward with a speed u from the top of the tower reaches the ground with a velocity 3u. The height of the tower is
(a) 3u2/g
(b) 4u2/g
(c) 6u2/g
(d) 9u2/g

B

Question. A particle is moving in a straight line with initial velocity and uniform acceleration a. If the sum of the distance travelled in tth and (t + 1)th seconds is 100 cm, then its velocity after t seconds, in cm/s, is
(a) 80
(b) 50
(c) 20
(d) 30

B

Question. Similar balls are thrown vertically each with a velocity 20 ms–1, one on the surface of earth and the other on the surface of moon. What will be ratio of the maximum heights attained by them? (Acceleration on moon = 1.7 ms–2 approx)
(a) 6
(b) 1/6
(c) 2/5
(d) None of these

B

Question. An automobile travelling with a speed of 60 km/h, can apply brake to stop within a distance of 20m. If the car is going twice as fast i.e., 120 km/h, the stopping distance will be
(a) 60 m
(b) 40 m
(c) 20 m
(d) 80 m

D

Question. A rocket is fired upward from the earth’s surface such that it creates an acceleration of 19.6 ms-2 . If after 5 s, its engine is switched off, the maximum height of the rocket from earth’s
surface would be
(a) 980 m
(b) 735 m
(c) 490 m
(d) 245 m

B

Question. If you were to throw a ball vertically upward with an initial velocity of 50 m/s, approximately how long would it take for the ball to return to your hand? Assume air resistance is negligible.
(a) 2.5 s
(b) 5.0 s
(c) 7.5 s
(d) 10 s

D

Question. A body travels 2 m in the first two second and 2.20 m in the next 4 second with uniform deceleration. The velocity of the body at the end of 9 second is
(a) – 10 ms-1
(b) – 0.20 ms-1
(c) – 0.40 ms-1
(d) – 0.80 ms-1

B

Question. The motion of a particle is described by the equation u = at. The distance travelled by particle in first 4 sec is
(a) 4a
(b) 12a
(c) 6a
(d) 8a

D

Question. From a 200 m high tower, one ball is thrown upwards with speed of 10 ms-1 and another is thrown vertically downwards at the same speeds simultaneously. The time difference of their reaching the ground will be nearest to
(a) 12 s
(b) 6 s
(c) 2 s
(d) 1 s

C

Question. Six persons are standing of a regular hexagon of side ‘a’. Each person starts moving towards the person standing at the adjacent corner with speed ‘v’. They will meet after a time
(a) 3v/a
(b) 6v/a
(c) a/6v
(d) 2a/v

D

Question. Two vectors A̅ = 2𝑖̂ + 3 𝑗̂ – y𝑘̂ and B̅ = x𝑖̂ – ˆj + 3𝑘̂ are given. If (A̅ + B̅ ) is a vector of magnitude 2 along +y axis then the values of x and y will be
(a) 2, 3
(b) –2, 3
(c) 2, –3
(d) –2, –3

B

Question. A projectile is fired with a speed u at an angle ′θ′ with the horizontal. When its direction of motion makes an angle α with the horizontal, its speed at that instant is
(a) u cos α sec θ
(b) u cos θ sec α
(c) u cos θ / sec α
(d) u secθ /cos α

B

Question. In the situation shown in figure, the three concurrent forces F1, F2 and F3 are in equilibrium then

A

Question. A body of mass 7 kg at rest explodes into three fragments having masses in the ratio 3 : 3 : 1. The fragments with equal masses fly in mutually perpendicular directions with speed 15 ms–1. What will be the speed of the lighter fragment?
(a) 15 m/s
(b) 15√2 m/s
(c) 45 m/s
(d) 45√2 m/s

D

Question. Two projectile projected from ground towards each other with same initial speed u but at angles θ and (90 – θ) from horizontal. If initial separation between them is equal to range (R) of projection, then time after which they cross same vertical line is
(a) R/ cosθ
(b) R/sinθ
(c) R/u( sinθ + cosθ)
(d) R/u2( sinθ + cosθ)

C

Question. Stairs of height 1 m and width 2 m are as shown in figure. Minimum horizontal velocity u given to the ball A for which it will hit water directly is
(a) √10 m/s
(b) 2√10 m/s
(c) 4√10 m/s
(d) √10/2 m/s

B

Question. A river (width = 200 m) is flowing at a speed of 3 km/h. A man swims across the river along the shortest path and swims back the same way. If the velocity of swimming of man is 5 km/h in still water then time taken by the man for his round trip is
(a) 1/10 h
(b) 1/20 h
(c) 1/40 h
(d) 1/60 h

A

Question. Choose correct relation [where s, θ and r are displacement of particle, angular displacement and radius of circle respectively]

A

Question. Unit vector of a vector A = 3𝑖̂ + 8 𝑗̂ − 𝑘̂is
(a) A/√74
(b) A/√72
(c) A̅
(d) Zero