OBJECTIVE PRACTICE QUESTIONS-1

General Physics
Objective Question
Q.1      The fundamental unit which has same power in the dimensional formula of surface tension and      viscosity is :
(a)        Mass                (b)        Length             (c)        Time                (d)        None
Q.2       Indicate which pairs of  physical quantities given below has not the same units and dimensions :
(a)               Momentum and impulse
(b)               Torque and angular momentum
(c)                Acceleration and gravitational field strength
(d)               Pressure and modulus of elasticity
Q.3      The dimensions of pressure are :
(a)        [MLT-2]            (b)        [ML-1T2]              (c)        [ML-1T-2]             (d)        [MLT2]
Q.4      The dimensions of torque are :
(a)        [M L2 T-2]         (b)        [M L T-2]         (c)        [M L-1 T--2]      (d)        [ML-2 T-2]
Q.5      The dimensional formula for angular momentum is :
(a)        [M0L2T-2]         (b)        [ML2T-1]           (c)        [MLT-1]            (d)        [ML2T-2]
Q.6      Planck’s constant has the dimensions of :
(a)        Energy             (b)        Momentum      (c)        Frequency       
(d)        Angular momentum
Q.7      The dimensional formula for Planck’s constant is :
(a)        [ML2T-1]           (b)        [ML2T3]           (c)        [ML-1T-2]          (d)        [MLT-2]
Q.8      The dimensions of gravitational constant G are :
(a)        [MLT-2]            (b)        [ML3T-2]           (c)        [M-1L3T-2]         (d)        [M-1LT-2]
Q.9      The dimensional formula for modulus of rigidity is :
(a)        [ML-1T-1]                      (b)        [ML-2T2]              (c)        [MLT-1(d)     [ML-1T-2]
Q.10    Turpentine oil is flowing through a tube of length l and radius r. The pressure difference between the two ends of the tube is p; the viscosity of the oil is given by :
                                    h = p (r2 – x2)/4nl
where v is the velocity of oil at a distance x from the axis of the tube. From this relation, the dimensions of viscosity h are :
(a)        [M0L0T0]                                                          (b)        [MLT-1]               
(c)        [ML2T-2]                                                                              (d)        [ML-1T-1]
Q.11    The velocity n of a point at time t is given by :
                                     n = at + b/ (t + c)
            The dimensions of a, b and c are respectively :
(a)        L2; T and LT2                                                   (b)        LT2; LT and L                         
(c)        LT-2; L and T                                                   (d)        L; LT and T2   
Q.12    The time dependence of a physical quantity p is given by P = P0 exp (-at2) [where a is a constant and t is time]. The constant a
(a)        is dimensions [T2]                                            (b)        has dimensions [T-2]                            (c)        is dimensions                                                      (d)        is dimensions of p
Q.13    The velocity of water waves may depends on their wavelength l, the density of water r and the acceleration due to gravity g. The method of dimensions gives the relation between these quantities as :
(a)        V2 µ g-1 l-1                                                       (b)        V2 µ gl                                   
(c)        V2 µ glr                                                          (d)        V2 µ g-1 l-3
Q.14    The time period T of a small drop of liquid (due to surface tension) depends on density r, radius r and surface tension S. The relation is :
(a)        T µ (rr3/S)1/2                                                    (b)        T µ rrS                       
(c)        T µ rr/S                                                           (d)        T µ (S/rr)
Q.15    P represents radiation pressure, c represents speed of light and S represents radiation energy striking unit area per sec. The non zero integers x, y and z such that PxSycz is dimensionless are :
(a)        x = 1, y =1, z = 1                                             (b)        x = -1, y =1, z = 1       
(c)        x = 1, y =-1, z = 1                                           (d)       x = 1, y =1, z = 1
Q.16    The measured mass and volume of a body are 23.42 g and 4.9 cm3 respectively with possible error 0.01 g and 0.1 cm3. The maximum error in density is nearly
                        (a)        0.2%                (b)        2%                   (c)        5%       (d)        10%    
Q.17    The least count of a stop watch is 0.2 second. The time of 20 oscillations of a pendulum is measured to be 25 second. The percentage error in the measurement of time will be
(a)        8%                   (b)        1.8%                (c)        0.8%   (d)        0.1%  
Q.18    A student measures quantities a,b and c and then calculates S by the formula S = ab2/c3. If the errors in a,b,c are 1%, 3% and 2% respectively, the maximum error in S can be :
                        (a)        13%                 (b)        7%                   (c)        4%       (d)        1%
Q.19    The percentage errors in the measurement of mass and length of the edge of a cube are 3% and 2% respectively. The maximum percentage errors in the density would be :
(a)        1%                   (b)        5%                   (c)        9%                   (d)        11%  
Q.20    The pressure on a square plate is measured by measuring the force on the plate and the length of the side of the plate. The errors in the measurement of force and length are 4% and 2% respectively. The maximum error in the value of the pressure would be
(a)        1%                   (b)        2%                   (c)        6%                   (d)        8%  
Q.21    Four persons measure the thickness of a paper and express it in the following way. Which measurement is maximum accurate?
                        (a)        3.00 ´ 10-4 m                                       (b)        30 ´ 10-3 cm   
(c)        3 ´ 10-2 cm                                          (d)        0.030 cm.
Q.22    The length and breadth of a metal sheet are 3.124m and 3.002 m respectively. The area of this sheet up to four correct significant figures is 
(a)        9.3m2                                                   (b)        9.378m2          
(c)        9.3782m2                                             (d)        9.378248m2.
Q.23    Which of the following measurements is most significant?
                        (a)        0.003 mm        (b)        3.00 mm          (c)        30.00 mm        (d)        3.0 mm

Q.24    A vectors A points vertically upwards and B points toward north. The vectors produced A ´ B is :
(a)               along west                    (b)        along east
(c)                zero                             (d)        vertically downwards
Q.25    Which of the following physical quantities are represented by polar vectors?
(a)        Displacement                           (b)        Angular Velocity
(c)        Angular momentum                 (d)        Torque
Q.26    The flight of a bird can be example of :
(a)        dot product of vectors                         (b)        cross product of vectors
(c)        composition of vectors                        (d)        Triangle law of vector addition
Q.27    The vectors A and B are such thatú A + Bú =ú ABú  then the angle between the two vectors A and B will be
(a)        0°                     (b)        60°       (c)        90°                   (d)        180°
Q.28    Two vectors A and B are such that A + B = C and  A2 + B2 = C2. If  q is the angle between positive directions A and B then mark the correct alternative :
(a)        q = 0°              (b)        q = p/2 (c)        q = 2p/3           (d)        q = p
Q.29    A + B = C, the angle between A and B is 120° and   A = B. If A + B + C = 0°. Then what is the angle between A and B?            
(a)        30°                   (b)        60°       (c)        120°                 (d)        150°
Q.30    If | P | = | Q | and the angle between P and Q is neither 0° nor 180°, then what is the angle between P + Q and      PQ?
(a)        0°                     (b)        30°       (c)        60°       (d)        90°



Answer Sheet

General Physics
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Kinematics

DISTANCE, DISPLACEMENT AND VELOCITY,ACCLERATED MOTION

Q.1       A ball is thrown vertically upwards from the ground G with a speed u. It reaches a point B at a height h (lower than the maximum height) after time t1. It return to the ground after time t2 from the instant it was at B during the upward journey. Then t1t2 is equal to :
(a)        2h/g                  (b)        h/g                   (c)        h/2g                  (d)        h/4g
Q.2       A ball is dropped from the top of the tower of height h. It covers a distance of h/2 in the last second of its motion. How long does the ball remain in air? (Take g = 10 ms-2)
(a)        Ö2s                   (b)        (2 ±Ö2)s            (c)        2s                    
(d)        none of these
Q. 3      A bus is moving with a velocity 10 ms-1 on a straight road. A scooterist wishes to cover-take the bus in 100 s. If the bust is a distance of 1 km from the scooterist, with what velocity should the scooterist chase the bus?
(a)        50 ms-1             (b)        40 ms-1             (c)        30 ms-1             (d)        20 ms-1
Q.4       A car is moving eastwards with velocity 10 m/s. In 20 sec, the velocity changes to 10 m/s northwards. The average acceleration in this time :
(a)        1/Ö2 ms-2 towards N-W                           (b)        1/Ö2 ms-2 towards N-E
(c)        ½ ms-2 towards N-W                              (d)        ½ ms-2 towards N-E
Q.5       A body starts from rest with a uniform acceleration of 2 m/s2 for 10 sec, it moves with constant speed for 30 sec then decelerates by 4 m/s2 to zero. What is the distance covered by the body?
(a)        750 m               (b)        850 m               (c)        600 m              
(d)        none of these
Q.6       A body dropped from a height h with an initial speed zero reaches the ground with a velocity of 3 km/h. Another body of the same mass was dropped from the same height h with an initial speed 4 km/h, will reach the ground with a velocity of :
(a)        3 km/h              (b)        4 km/h              (c)        5 km/h              (d)        12 km/h
Q.7       A parachutist after bailing out falls 50 m without friction when parachute opens, it decelerates at 2 m/s2. He reaches the ground with a speed of  3 m/s. At what height, did he bail out? 
(a)        293 m               (b)        111m                (c)        91 m                 (d)        182 m
Q.8       A car covers 1/3 distance with speed 20 km/hr and 2/3 with 60 km/hr. Average speed is :
(a)        40 km/hr                                   (b)        50Ö2 km/hr       
(c)        36 km/hr                                   (d)        48 km/hr.
Q.9       A particle is thrown vertically upwards. Find the velocity so that it covers same distance in 5th and 6th seconds :
(a)        48 m/s              (b)        14 m/s              (c)        49 m/s              (d)        7 m/s.
Q.10     From the top of a tower, a particle is thrown vertically downwards with a velocity of 10 m/s. The ratio of the distance covered by it in the 3rd and 2nd seconds of the motion is :
(a)        5 : 7                  (b)        7 : 5                  (c)        3 : 6                  (d)        6 : 3.
Q.11     A ball is thrown from height h and another from 2h. The ratio of time taken by the two balls to reach ground is : 
(a)        1: Ö2                 (b)        Ö2 : 1                (c)        2 : 1                  (d)        1 : 2.
Q.12     Two bodies A (off mass 1 kg) and B (of mass 3 kg) are dropped from height 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.

Q.13     A particle is moving eastwards in a velocity of 5m s-1. In 10 seconds the velocity changes to 5m s-1 northwards. The average acceleration in this time is
(a)        zero                                          (b)        1/Ö2 m s-2 towards north-west
(c)        1/Ö2 m s-2 towards north-east     (d)        ½ m s-2 towards north.
Q.14     A-Train covers one half of its journey between two stations with speed v1 and the remaining half with speed v2. The average speed for the whole journey is
(a)        v1+v2/2              (b)        2 v1v2 / v1+v2      (c)        Ö v1v2                                (d)        Ö v1/v2
Q.15     A 150 m long train is moving north at a speed of 20m/s. A bird flying south at a speed of 5m/s cross the train. What is the time taken by the bird to cross the train
(a)        30s                   (b)        10s                   (c)        7.5s                  (d)        6s
Q.16     From a 20 m high tower one ball is thrown upwards with speed of 10m/s and another is thrown vertically downwards at the same speed simultaneously. The time difference of their reaching the ground will be     (Take g = 10ms-2
(a)        12s                   (b)        6s                     (c)        2s                     (d)        1s
Q.17     A particle is projected vertically upwards. It attains a height h after 2 seconds and again after 10 seconds. The speed of the particle at the height h is numerically equal to
(a)        g                      (b)        2g                     (c)        4g                     (d)        6g
Q.18     Two objects begin free fall from rest from the same height with a time gap of 1s. How long after the first object begins to fall will the two bodies be 10m apart.
(a)        3.5s                  (b)        2s                     (c)        0.5s                  (d)        1.5s
Q.19     If the speed of a truck is reduced to 1/3 of its original value, the minimum distance required to stop will be
(a)        same as before                                     (b)        1/3 of its original value
(c)        1/9 of its original value              (d)        2/3 of its original value 
Q.20     The magnitude of average velocity is equal to the average speed when a particle moves :
(a)        on a curved path                       (b)        in the same direction
(c)        with constant acceleration          (d)        with constant retardation
Q.21     If a particle moves with a constant velocity :
(a)        its acceleration is positive          (b)        its acceleration is negative
(c)        its acceleration is zero               (d)        its speed is zero 
Q.22     A particle moving in a straight line cover half the distance with speed of 3 m/s. the other half of the distance is covered in two equal time intervals with speed of 4.5m/s and 7.5 m/s respectively. The average speed of the particle during this motion is : 
(a)        4 m/s                (b)        5 m/s                (c)        5.5 m/s             (d)        4.8 m/s
Q.23     A ball is released from the top of a tower of height h meters. It takes T seconds to reach the ground. What is the position of the ball at T/3 second ?      
(a)        8h/9 meters from the ground                  (b)        7h/9 meters from the ground
(c)        h/9 meters from the ground                    (d)        17h/18 meters from the ground
Q.24     If a train traveling at 72 km/h is to be brought to rest in a distance of 200m, then its retardation should be :
(a)        20 m/s2             (b)        2 m/s2               (c)        10 m/s2             (d)        1 m/s2
Q.25     A body travels 200 cm in the first two seconds and 220 cm in the next 4 sec with deceleration. The velocity of the body at the end of the 7th second is :    
(a)        5 cm/s              (b)        10 cm/s                        (c)        15 cm/s                        (d)        20 cm/s
Q.26     A car moving with a speed of 40 km/hr, can be stopped by applying brakes after at least 2m. If the same car is moving with a speed of 80 km/hr, what is the minimum stopping distance?     
(a)        2 m                   (b)        4 m                   (c)        6 m                   (d)        8 m.

Q.27     An electron of mass me, initially at rest, moves through a certain distance in a uniform electric field in time t1. A proton of mass mp, also initially at rest, takes time t2 to move through an equal distance in this uniform electric field. Neglecting the effect of gravity, the ration t2/t1 is nearly equal to :
(a)        1          (b)        (mp/me)1/2                      (c)        (me/mp)1/2           (d)        1836
Q.28     A particle is dropped vertically from rest, from a height. The time taken by it to fall through successive distance of 1 km each will then be :
(a)        all equal, being equal to Ö2/g second
(b)           in the ratio of the square roots of the integers 1, 2 3, . . .
(c)           in the ratio of the difference in the square roots of the integers, i.e., Ö1, (Ö2 - Ö1),             (Ö3 - Ö2), (Ö4 - Ö3), . . .
(d)           in the ratio of the reciprocal of the square roots of the integers, i.e, 1/Ö1 , 1/Ö2 , 1/Ö3 ,  . . .
Q.29     An object accelerates from rest to a velocity 27.5 m/s in 10 sec, then find distance covered by next 10 sec: 
(a)        550 m               (b)        137.5 m            (c)        412.5 m            (d)        275 m.
Q.30     A body falls freely from rest. It covers as much distance in the last second of its motion as covered in the first three second. The body has fallen for a time of :
(a)        3 s                    (b)        5 s                    (c)        7 s                    (d)        9 s



Answer Sheet

DISTANCE, DISPLACEMENT AND VELOCITY,ACCLERATED MOTION


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Graph & Problems on Integration and Differentiation

Q.1      A particle moves along x-axis in such a way that its coordinate x varies with time t according to the expression
x = 2 – 5t + 6t2
            The initial velocity of the particle is                                                                                                                             (a)        - 5m/s              (b)        -3 m/s              (c)        3 m/s                (d)        6 m/s
Q.2      A particle starts from rest and travels in a straight line with an acceleration which varies with time t as follows
                                                                        a = 6 – 2 t
            The distance traveled by the particle in 3s is                                                                                                                (a)        9 m                  (b)        12 m                (c)        15 m                (d)        18 m
Q.3      A bird flies in straight line for 4s with a velocity n = (2t - 4) m/s. What is the distance covered by the bird in returning to the place from where it started its journey?                                                                      (a)        0                        (b)        8 m                  (c)        4 m                  (d)        2 m
Q.4      A particle starts from rest at the origin and moves along X-axis with acceleration
                                                                        a = 12 – 2 t
            The time after which the particle arrives at the origin is                                                                                              
                        (a)        6 s                    (b)        18 s                  (c)        12 s                  (d)        4 s
Q.5      The position x of a particle varies with time (t) as x = at2 – bt3. The acceleration at time t of the particle will be equal to zero, where t is equal to : 
(a)        2a/3b               (b)        a/b                   (c)        a/3b                 (d)        zero
Q.6      The displacement s of a particle is proportional to the first power of time t, i.e., s µ t, then the acceleration of the particle is :
                        (a)        infinite                                                             (b)        zero
                        (c)        a small finite value                              (d)        a large finite value
Q.7      The displacement s of a particle is proportional to the second power of time t, i.e., s µ t2, then the initial velocity of the particle is :
                        (a)        infinite                                                             (b)        zero
                        (c)        positive finite value                             (d)        negative finite value
Q.8      The distance traveled by a particle is directly proportional to t1/2, where t = time elapsed. What is the nature of motion?
                        (a)        Increasing acceleration                                    (b)        Decreasing acceleration
                        (c)        Increasing retardation                          (d)        Decreasing retardation
Q.9      The displacement of a body is given by 4s = M + 2Nt4, where M and N are constants. The velocity of the body at any instant is :
                        (a)        M + 2Nt4/4       (b)        2N                   (c)        M + 2 N/4        (d)        2Nt3
Q.10    The acceleration of particle, starting from rest, varies with time according to the relation :
                                    A = -sw2 sin wt
            The displacement of this particle at a time t will be : 
(a)        s sin wt             (b)        sw cos wt         (c)        sw sin wt(d)      ½ (sw2 sin wt)t2
Q.11    If x denotes displacement in time t and x = a cos t, then acceleration is :
                        (a)        a cos t              (b)        - a cos t                        (c)        a sin t               (d)        -a sin t
Q.12    The relation between time t and distance x is t = ax2 + bx where a and b are constants. The acceleration is :            
                        (a)        -2av3               (b)        2bv3                      (c)        -2abv3             (d)        2b3v3
Q.13    The velocity time relation of an electron starting from rest is given by v = kt where k = 2 m/s2. The distance traversed in 3 sec is :
(a)        9 m                  (b)        16 m                     (c)        27 m                (d)        36 m
Q.14    A particle moves along a straight line such that its displacement at any time t is given by
                                                S = (t3 – 3t2 + 2)m
            The displacement when the acceleration becomes zero is :
(a)        0 m                  (b)        2 m                        (c)        3 m                  (d)        -2 m
Q.15    A point moves in a straight line so that its displacement x m at time t sec is given by x2 = 1 + t2. Its acceleration in m/sec2 at a time t sec is
(a)        1/x3                                                      (b)        -t/x3                      
(c)        1/x – t2/x3                                             (d)        1/x – 1/x3
Q.16    A body is moved along a straight line by a machine delivering constant power. The distance moved by the body in time t is proportional to :
                        (a)        t1/2                    (b)        t3/4                          (c)        t3/2                    (d)        t2
Q.17    The displacement of a particle after time t is given by x = (k/b2)(1 –e-bt), where b is a constant. What is the acceleration of the particle?
(a)        ke-bt                  (b)        -ke-bt                      (c)        k/b2e-bt             (d)        -k/b2e-bt           
Q.18    The velocity v and displacement r of a body are related as v2 = kr, where k is a constant. What will be the velocity after 1 second? Given that the displacement is zero at t = 0 :
(a)        Ök r                                                                  (b)        k r3/2                     
(c)        k/2r0                                                                 (d)        data is not sufficient
Q.19    A particle’s position as a function of time is described as y (t) = 2t2 + 3t + 4. What is the average velocity of the particle from t = 0 to t = 3 sec?
(a)        3 m/s                (b)        6 m/s                     (c)        9 m/s                (d)        12 m/s
Q.20    The displacement x of a particle moving in one dimension under the action of constant force is related to time t by the equation t = Öx + 3, where x is in metres and t is in seconds. Find the displacement of the particle when its velocity is zero.   
(a)        zero                 (b)        12 m                     (c)        6 m                  (d)        18 m               
Q.21    A travelling wave in a stretched string is described by the equation  y =A sin (kx -w t)            The maximum particle velocity is
                        (a)        Aw                   (b)       w/k                   (c)        dw/dt                (d)        x/t
Q.22    The x and y coordinates of a particle at any time t are given by :
                                    x = 7t + 4t2       and      y = 5t
            Where x and y are in m and t in s. The acceleration of the particle at 5s  is :              
(a)        zero                 (b)        8 m/s2                   (c)        20 m/s2                        (d)        40 m/s2
Q.23    The position vector of a particle is given by r = r0 (1 - at)t, where t is the time and a as well as r0 are constants. After what time the particle returns to the starting point ?
(a)        a                      (b)       1/a                   (c)        a2                     (d)        1/a2
Q.24    The acceleration of a particle varies with time as a = bt + c, where b and c are constant. What will be the velocity of the particle which starts from rest after the time t?
(a)        bt + 1/2ct2        (b)       ct + ½ bt2            (c)        bt + ct2             (d)        ct + bt2
Q.25    A body is moving according to the equation :
                                    x = at + bt2 – ct3
            where x = displacement and a, b and c are constants. The acceleration of the body is :
                        (a)        a + 2bt                                                 (b)       2b + 6ct          
(c)        2b – 6ct                                                           (d)        3b – 6ct2

Answer Sheet

1.
(a)
2.
(d)
3.
(b)
4
(b)
5.
(c)
6.
(b)
7.
(b)
8.
(d)
9.
(d)
10.
(a)
11.
(b)
12.
(a)
13.
(a)
14.
(a)
15.
(c)
16
(c)
17.
(b)
18.
(c)
19.
(c)
20.
(a)
21.
(a)
22.
(b)
23.
(b)
24.
(b)
25.
(c)















PROJECTILE MOTION
Q.1      An object is thrown along a direction inclined at an angle of 45° with the horizontal. The horizontal range of the particle is equal to

(a)        vertical height                                                  (b)        twice the vertical height
(c)        thrice the vertical height                                   (d)        four the vertical height

Q.2      The greatest distance to which a man can throw a stone is a. The greatest height to which he can throw it will be

(a)        a                      (b)        a/2                   (c)        2/ a                  (d)        a/3

Q.3      Two bodies are projected from the same point with the same speed but in different directions so as to have the same range. The ratio of their times of flight are

(a)        1:1                   (b)        1: cos q                        (c)        1: sin q             (d)        1: cot q

Q.4      The range of projectile which is launched at an angle of 15° with the horizontal is 1.5km. What is the range of the projectile if it is projected at an angle of 45° to the horizontal?

(a)        1.5km              (b)        3.0km              (c)        6.0km              (d)        0.75km

Q.5      A man has two spheres A and B. He is standing at the top of a tower. He gently drops the sphere A vertically downwards and throws the sphere B horizontally at the same time. Which of the following is the correct statement?

(a)        both the sphere will reach the ground simultaneously
(b)        sphere A will reach the ground earlier
(c)        sphere B will reach the ground earlier
(d)        the question is incomplete because the masses of the sphere are not given

Q.6      The range of projectile is 24m and the maximum height reached is 8m. The initial velocity and angle of projection are

(a)        6Ög , sin-1(0.8)                                                             (b)        5Ög , sin-1(0.6)
(c)        5Ög , sin-1(0.8)                                                 (d)        4Ög , sin-1(0.6)

Q.7      A particle is projected with the speed of 10Ö5m/s at an angle of 60° from the horizontal, the velocity in m/s of the projectile when it reaches the height of 10m is (Take g=9.8m/s)

(a)        4Ö19                (b)        Ö179                (c)        15                    (d)        5Ö15

*Q.8    A lift is moving vertically upwards. At the instant when its velocity is v and downward acceleration is a (<g), a stone is projected from a point on its floor at an angle q with the horizontal. The trajectory of the stone is

(a)               a parabola in the lift frame                  (b)        a parabola in the ground frame
(c)        a straight line in the lift frame              (d)        a straight line in the ground frame

Q.9      A particle is projected with a velocity of 19.6m/s at an angle of 30° with the horizontal. It will move at right angles to its initial directions of motion after a time of

(a)        2s                     (b)        6s                     (c)        4s                     (d)        8s

Q.10    A particle of mass m is projected from a point A at an angle of 45° with the horizontal with a speed v. If the time taken to reach the highest point B is t, What is the change in its velocity from its departure at A to its arrival at B?

(a)        Ö2v                  (b)        v/Ö2                 (c)        gt                     (d)        ½ gt2

Q.11    A projectile of mass m is fired with the velocity v from ground at an angle of 45° with horizontal. Neglecting air resistance, the magnitude of change in momentum between leaving and arriving at the ground is

(a)        zero                 (b)        ½ mv                (c)        Ö2 mv               (d)        2mv

Q.12    A shell is fired a cannon with a velocity v at an angle q with the horizontal direction. At the highest point in its path it explodes into two pieces of equal mass. One of the pieces retraces its path to the canon and the speed of the other piece immediately after the explosion is

(a)        3v cos q           (b)        2v cosq                        (c)        3/2 v cos q       (d)        Ö3/2 v cosq

Q.13    A body of mass 1kg is thrown from a point A with a velocity 20m/s at an angle 45° with the horizontal. If the highest point attained by it is B, calculate the work done by the gravity during its journey from A to B. (g= take 10 m/s2)

(a)        200J                 (b)        –200J               (c)        –100J               (d)        100J

Q.14    A body of mass 1kg is thrown with a velocity 40m/s at an angle of 30° with the horizontal. What is the change in its momentum during the interval 1.0s to 3.0s (Take g = 10m,/s2)

(a)        –20kg ms-1         (b)        40kg ms-1            (c)        0                      (d)        –40 kg ms-1

Q.15    A body of mass 1kg is thrown with a velocity of 40m/s at an angle of 30° with the horizontal. Calculate the work done by the gravity during the interval of 1.0s to 3.0s      (Take g = 10m,/s2)

(a)        800J                 (b)        400J                 (c)        –800J               (d)        0
*Q.16  In case of projectile motion of two projectiles A and B are projected with the same speed at angles 15° and 75° respectively to the horizontal, then 

(a)        HA > HB               (b)        HA < HB               (c)        TA > TB                                (d)        TA < TB           

Q.17    A projectile of mass m is fired with velocity v pass a point A making an angle 45° with the horizontal. Neglecting air resistance, the magnitude of change in momentum between the starting point A and the arriving point B is

(a)        Ö2 mv               (b)        2 mv                 (c)        (1 - 2) m v       (d)        (mv)1/2

Q.18    A particle is thrown with a speed u at an angle q with the horizontal. When the particle makes an angle f with the horizontal, its speed changes to v, which is equal to
(a)        u cos q            (b)        u cos q cos f    (c)        u cos q sec f    (d)        u sec q cos f
Q.19   A cannon ball has the same range R on a horizontal plane for two angles of projection. If h1 and h2 are the greatest heights in the two paths for which this possible, then  
(a)        R = (h1h2)1/4     (b)        R = Öh1h2            (c)        R = 4 Öh1h2        (d)        R = Öh1h2
Q.


































































20    Two balls are projected making angles of 30° and 45° respectively with the horizontal. If both have same velocity at th4e highest point of their path, then the ratio of their horizontal range is  
(a)        1:3                   (b)        3: 1                  (c)        Ö3: Ö2              (d)        1: Ö3
Q.21    A particle is projected at an elevation tan-1 (5/3) from a point O. The ratio of the range on the horizontal plane through O to the greatest height ascended above O is
(a)        2                      (b)        2.4                   (c)        0.4                   (d)        1.5
Q.22    After one second the velocity of a projectile makes an angle of 45° with the horizontal. After another one second it is traveling horizontally. The magnitude of its initial velocity and angle of projection are (g = 10 m/sec2
(a)        14.62 ms-1, tan-1 (2)                                          (b)        22.36 ms-1, tan-1 (2)
(c)        14.62 ms-1, 60°                                                            (d)        22.36 ms-1, 60°           
Q.23    A particle is projected from the ground with an initial speed of u at an angle q with horizontal. The average velocity of the particle between its point of projection and highest point of trajectory is        
(a)        u cos q                                                            (b)        u/2 Ö1 + cos2 q            
(c)        u/2 Ö1 + 2cos2 q                                               (d)        u/2 Ö1 + 3 cos2 q
Q.24    The maximum height attained by a projectile is increased by 5%. Keeping the angle of projection constant, what is percentage increase in the horizontal range?           
(a)        5%                   (b)        10%                 (c)        15%                 (d)        20%
Q.25    The maximum height attained by a projectile is increased by 10%. Keeping the angle of projection constant, what is percentage increase in the time of flight?        
(a)        5%                   (b)        10%                 (c)        20%                 (d)        40%
Q.26    The equation of motion of a projectile is :                   y = 12x – 3/4 x2
The horizontal component of velocity is 3ms-1. Given that g = 10 ms-2, what is the range of the projectile?   
(a)        12.4m              (b)        21.6m              (c)        30.6 m             (d)        36.0 m
Q.27    A body is projected is up a smooth inclined plane with velocity V from the point A as shown in the figure. The angle of inclination is 45° and the top is connected to a well of diameter 40 m. If the body just manages to cross the well, what is the value of V? Length of inclined plane is 20Ö2 m. 
(a)        40 ms-1             (b)        40Ö2 ms-1         (c)        20 ms-1             (d)        20Ö2 ms-1
Q.28    Galileo writes that for angles of projection of a projectile at angles (45 + a) and (45 - a), the horizontal ranges described by the projectile are in the ratio of :    
(a)        2 : 1                 (b)        1 : 2                 (c)        1 : 1                 (d)        2 : 3
Q.29    A projectile is fired from level ground at an angle q above the horizontal. The elevation angle f of the highest point as seen from the launch point is related to q by the relation :
(a)        tan f =1/4 tan q                                                            (b)        tan f = tan q
(c)        tan f = 1/2 tan q                                               (d)        tan f = 2 tan q
Q.30    Which of the following is the essential characteristic of a projectile?
(a)               Initial velocity inclined to the horizontal          (b)        Zero velocity at the highest point
(b)               Constant acceleration perpendicular to the velocity
(c)                None of the above

ANSWERSHEET
Projectile Motion
1.
(d)
2.
(b)
3.
(d)
4.
(b)
5.
(a)
6.
(c)
7.
(a)
8.
(a), (b)
9.
(c)
10.
(c)
11.
(c)
12.
(a)
13.
(c)
14.
(a)
15.
(d)
16.
(b), (d)
17.
(a)
18.
(c)
19.
(c)
20
(d)
21.
(b)
22.
(b)
23.
(d)
24.
(a)
25.
(a)
26.
(b)
27.
(d)
28.
(c)
29.
(c)
30.
(d)

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