Q.1.
A river is flowing from west to east at a speed of 5m/min. A man on the south bank of the river, capable of swimming at 10 m/min in still water, wants to swim across the river in shortest time. He should swim in a direction
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0%
a)due north
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100%
b) 30° east of north
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0%
c)30° west of north
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0%
d)60° east of north
Q.2.
A particle is moving eastwards with velocity of 5m/sec. In 10 sec the velocity changes to 5m/sec north-wards. the average acceleration in this time is [ CPMT 1998]
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0%
a) zero
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50%
b) (1/√2) m/sec2 towards north-west
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50%
c)30° west of north
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0%
d)60° east of north
Q.3.
The magnitude of a given vectors with end points (4, - 4, 0) and (-2, - 2, 0) must be
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a) 6
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100%
b) 5√2
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c)4
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0%
d)2√10
Q.4.
Choose the wrong statement
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a) Three vectors of different magnitudes may be combined to give zero resultant
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0%
b) Two vectors of different magnitudes can be combined to give a zero resultant
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0%
c) The product of a scalar and vector is a vector quantity
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100%
d) All above statements are wrong statement
Q.5.
A boat is sent across a river with velocity of 8km/h. If the resultant velocity of the boat is 10km/h, the river is flowing with velocity of [ CBSE 1994]
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0%
a)12.8 km/hr
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100%
b) 6 km/hr
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0%
c)8 km/hr
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0%
d)10 km/hr
Q.6.
The angle between vectors ( A×B) and (B×A) is
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a) zero
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b) π
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100%
c)π/4
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0%
d)π/2
Q.7.
The vectors 3i - 2j + k and 2i + 6j + ck are perpendicular when
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a) c=6
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50%
b) c=1
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50%
c)c=3
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0%
d)c=8
Q.8.
If two forces are equal and their resultant is also equal to one of them, then angle between the two forces is
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a) 60°
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50%
b) 120°
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50%
c) 90°
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0%
d) 0°
Q.9.
A boy is hanging from a horizontal branch of tree. The tension in the arms will be maximum when angle between arms is
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a)0°
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0%
b) 30°
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100%
c)60°
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0%
d)120°
Q.10.
Find the value of c is A=0.4i + 0.3j+ck is a unit vector
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0%
a) 0.5
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50%
b) √(0.75)
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50%
c)1
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0%
d)can not be calculated
Q.11.
A bird is flying towards south with velocity 40km/hr and a train is moving with a velocity 40km/hr towards east. What is the velocity of the bird w.r.t. an observer in train
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a) 40√2 km/hr north-east
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100%
b) 40√2 km/hr south-east
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0%
c)40√2 km/hr south-west
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0%
d)40√2 km/hr north-west
Explanation
Q.12.
The area of a parallelogram formed from the vector A=i + 2j + 3k and B=3i - 2j + k as adjacent sides is
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50%
a) 8√3 units
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b) 64 units
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50%
c) 32 units
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0%
d) √3 units
Explanation
Q.13.
The resultant of two forces has magnitude 20 Newton. One of the forces is of magnitude 20√3 Newton and makes an angle of 30° with the resultant. Then, the other force must be of magnitude
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a)10N
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0%
b) 20 N
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50%
c)20√3 N
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50%
d)10√3 N
Q.14.
Two forces, one of 10N and other 6N act upon a body. The direction of the forces are unknown, the resultant force on the body is
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a) Not less than 4N and not more than 16N
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b) More than 15N always
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50%
c)More than 6N
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0%
d)More than 10N
Q.15.
The vector sum of N coplanar forces each of magnitude F, when each force is making an angle of 2π/N with the preceding one is
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a) N F
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50%
b)N (F/2)
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0%
c)F/2
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50%
d)zero
Q.16.
A boat moves with speed of 5km/hr relative to water in river flowing with speed of 3 km/hr and having a width of 1km. The time taken around trip is
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a) 5 min
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0%
b) 60 min
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50%
c) 20 min
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50%
d) 30 min
Q.17.
A vector A of magnitude 10 units and another vector of magnitude 6 units are acting at 60° to each other. The magnitude of vector product of two vector is
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a)30 units
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50%
b) 60 unit
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50%
c)30√3 unit
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0%
d)none of the above
Q.18.
The magnitude of vector can not be
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a) unity
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33%
b) positive
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67%
c)negative
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0%
d)zero
Q.19.
A river is flowing at the rate of 6 km/hr. A swimmer swims across with a velocity of 9 km/hr. The resultant velocity of the man will be in(km/hr)
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a) √(117)
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100%
b) √(340)
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0%
c)√(17)
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0%
d)3√(40)
Q.20.
The area of parallelogram with sides as A=2i + 3j and B=i + 4j
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0%
a) 5 units
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50%
b) 10 units
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0%
c) 15 units
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50%
d) 20 units
Q.21.
To a person going east in a car with velocity of 25 km/hr a train appearing to move towards north with velocity of 25√3 km/hr. The actual velocity of the train will be
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a)25 km/hr
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0%
b) 50km/hr
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50%
c)5 km/hr
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50%
d)5√3 km/hr
Explanation
Q.22.
At what angle two forces 2F and √2F acts, so that the resultant force is F√(10) N
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50%
a) 45°
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50%
b) 60°
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0%
c)120°
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0%
d)90°
Q.23.
A stone is dropped from the window of a train moving along a horizontal straight track, the path of the stone as observed by an observer on ground is
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a) straight line
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100%
b) parabolic
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0%
c)circular
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d)hyperbolic
Q.24.
A grasshopper can jump a maximum horizontal distance of 20 cm. If it spends negligible time on the ground, what is its speed of travel along the road
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a) √2 m/s
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0%
b) 1 m/s
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100%
c) (1/√2) m/s
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0%
d) can not be calculated
Q.25.
A particle is projected such that the horizontal range and vertical height are same. Then the angle of projection is
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a)π/4
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50%
b) tan-1(4)
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c)tan-1(1/4)
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50%
d)π/3
Explanation
Q.26.
The height y and the distance x along the horizontal plane of projectile on a certain planet ( with no surrounding atmosphere) are given by y=(8t-5t2) m and x=6t metre where t is in seconds. The velocity with which the projectile is projected is
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a) 8 m/sec
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0%
b) 6 m/sec
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50%
c) 10 m/sec
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50%
d) not obtainable from the data
Explanation
Q.27.
A gun fires two bullets at 60° and 30° with horizontal. The bullets strikes at same horizontal distance. The ratio of maximum height for the two bullets is in the ratio
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a)2:1
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0%
b) 3:1
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100%
c)4:1
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0%
d)1:1
Q.28.
A hose pipe lying on the ground shoots a stream of water upward at an angle of 60° to the horizontal. The speed of the water is 20m/sec as it leaves the hose. It will strike the wall 10 m away at a height of
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50%
a) 10.5 m
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0%
b) 12.32 m
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0%
c)10.0 m
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50%
d)20.0 m
Explanation
Q.29.
A particle having a mass 0.5 kg is projected under gravity with speed of 98m/s at an angle of 60°. The magnitude of the change of momentum of the particle after 10 seconds is
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a) 0.5 N-sec
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50%
b) 49 N-sec
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c)98 N-sec
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50%
d)490 N-sec
Q.30.
The range of a particle when launched at an angle of 15° with horizontal is 1.5km. What is the range of the projectile when launched at an angle of 45° to the horizontal.
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33%
a) 1.5 km
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0%
b) 3.0 km
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33%
c) 6.0 km
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33%
d) 0.75 km
Explanation
