Engineering Mechanics objective

8/17/2019 Engineering Mechanics objective

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Engineering Mechanics

1.Which of the following statement is correct?

a) A force is an agent which produces or tends to produce motion.

b) A force is an agent which stops or tends to stop motion.

c) A force may balance a given number of forces acting on a body.d) Both (a) and (b). Ans: d

. !n order to determine the effects of a force acting on a body" we must #now

a) !ts magnitude and direction of the line along which it acts.

b) !ts nature (whether push or pull).c) $oint through which it acts on the body.

d) All of the above. Ans: d

%. &or a non'concurrent force system to be in euilibrium

a) only the closure of force polygon is sufficient b) only the closure of funicular polygon is sufficient

c) both force polygon and funicular polygon must close

d) none of the above Ans: c

. !f a number of forces are acting simultaneously on a particle" then the resultant

of these forces will have the same effect as produced by the all the forces. *hisis #nown as"

a) $rinciple of physical independence of forces.

b) $rinciple of transmissibility of forces.c) $rinciple of resolution of forces.

d) +one of the above. Ans: a

,. A couple consists of

a) *wo li#e parallel forces of same magnitude.

b) *wo li#e parallel forces of different magnitudes.c) *wo unli#e parallel forces of same magnitude.

d) *wo unli#e parallel forces of different magnitudes. Ans: c

-. *he ami/s *heorem is applicable only for

a) 0oplanar forces b) +on'0oncurrent forcesc) 0oplanar and concurrent forces d) Any type of forces Ans: c

. !f a body is in euilibrium. We may conclude that

a) +o force is acting on the body

b) *he resultant of all the forces acting on it is 2ero.

c) *he moments of the forces about any point are 2ero.d) Both (b) and (c) Ans: d

3. !f the sum of all the forces acting on a body is 2ero" then the body may be in euilibrium provided the forces

area) 0oncurrent b) $arallel c) i#e parallel d) 4nli#e parallel Ans: a


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5. *he moment of inertia of a triangular section of base (b) and height (h) about an a6is through its c. g. and parallel to the base is given by the relation"

a) bh%71 b) bh%7 c) bh%7%- d) bh%73 Ans: c

18. !f the resultant of two forces has the same magnitude as either of the force" then the angle between the two

forces isa) %89 b) ,9 c) -89 d) 189 Ans: c

11. *he force polygon representing a set of forces in euilibrium is a

a) triangle b) open polygon c) closed polygon d) parallelogram Ans: c

1. *he angles between two forces to ma#e their resultant a minimum and a ma6imum respectively are

a) 89 and 589 b) 1389 and 589 c) 589 and 1389 d) 1389 and 89 Ans: d

1%. *he torue produced by a force depends oni) the magnitude of the force

ii) the direction of the force

iii) the point of application of the force relative to origin *he correct answer is

a) only (i) b) both (i) and (ii)c) both (i) and (iii) d) all (i)" (ii) and (iii) Ans: d

1. *he graphical method of determining the forces in the members of a truss is based on

a) method of oint b) method of sectionc) either method d) none of the two methods Ans: a

1,. *he time of flight of a proectile on un upward inclined plane depends upona) angle of proection b) angle of inclination of the plane

c) both ;a/ and ; b/ d) none of the above Ans: c

1-. e6ternal" acting on it


8. *he periodic time of a body moving with simple harmonic motion


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a) depends upon its amplitude under all conditions. b) is independent of its amplitude

c) depends upon its amplitude under certain conditions

d) has no relation with its freuency. Ans: b

1. *he freuency of vibration in case of simple harmonic motiona) means the number of cycles per second

b) represents time ta#en by the particle for one complete oscillationc) depends upon its amplitude.d) is directly proportional to its beat. Ans: a

. Which of the following statement is wrong?

a) *he matter contained in a body is called mass.

b) *he force with which a body is attracted towards the centre of the earth is called weight.

c) *he total motion possessed by a moving body is called impulsive forced) none of them Ans: d

%. *he unit of rotational inertia of a body in 0..@ system is

a) cm

b) #g'cm

c) gm'cm

d) gm'cm

%

Ans: c

. !n @! units" the units of force and energy are respectively

a) +ewton and watt b) yne and ergc) +ewton and oule d) #g'wt and oule Ans: c

,. ne +ewton is euivalent to

a) 1 #g'wt b) 5.31 #g'wt c) 531 dyne d) 175.31 #g'wt Ans: d

-. !f a body is lying on a plane whose inclination with the hori2ontal is less than

the angle of friction" theni) a force is reuired to move the body upwards

ii) a force is reuired to move the body downwardiii) the body will not be in euilibrium *he correct answer isa) only (i) b) only (ii) c) both (i) and (ii) d) both (i) and (iii) Ans: c

3. &ree body diagram is an

a) isolated oint with only body forces acting on it

b) isolated oint with internal forces acting on it

c) isolated oint with all the forces" internal as well as e6ternal" acting on it


5. *he total momentum of two bodies remains constant after collision or any other mutual action. *his is #nowas

a) aw of 0onservation of Comentum

b) +ewton/s aw of 0ollision of Dlastic Bodiesc) both (a) and (b)

d) none of them Ans: a

%8. *he loss of #inetic energy due to direct impact of two bodies depends on


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a) the mass of two bodies b) the initial velocities of two bodiesc) the final velocities of two bodies d) Both (a) and (b) Ans: d

%1. A particle is dropped from a height of % m on a hori2ontal floor" which has a coefficient of restitution with th

ball of 17. *he height to which the ball will rebound after stri#ing the floor is

a) 8., m b) 8., m c) 1.8 m d) 1., m Ans: b

%. *he force acting on a point on the surface of a rigid body may be considered to act

A: at the centre of gravity of the body

B: on the periphery of the body

C: on any point on the line of action of the force

D: at any point on the surface normal to the line of action of the force

Ans:c

%%. A number of forces acting simultaneously on a particle of a body

A: may not be replaced by a single force

B: may be replaced by a single force

C: may be replaced by a single force through 0.. of the body

D: may be replaced by a couple

Ans: b

%. $ic# up the incorrect statement from the following :

A: *he 0.. of a circle is at its centre

B: *he 0.. of a triangle is at the intersecton of its medians

C: *he 0.. of a rectangle is at the intersection of its diagonals

D: *he 0.. of a semicircle is at a distance of r 7 from the centre


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D: intersecting forces

Ans: B

%3. At a given instant ship A is travelling at - #m7h due east and ship B is travelling at 3 #m7h due north. *he

velocity of B relative to A is

A: #m7hrs

B: #m7hrs

C: 1 #m7hrs

D: 18 #m7hrs

Ans

%5. *he euation of motion of a particle starting from rest along a straight line is 6 = t% ' %t E ,. *he ratio of the

accelerations after , sec and % sec will be

A: B:% 0: :, Ans A

8. *he locus of the instantaneous centre of a moving rigid body" is

A: straight line

B: involute

C: centroid

D: spiral.

Ans 0

1. A proectile is thrown at an angle a to the hori2ontal with F velocity v. !t will have the ma6imum centripetal

acceleration


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A: at the start

B: at the top of the traectory

C: as it stri#es the ground

D: else where.

Ans: A

. *he unit of Coment of !nertia of a body" is

A: m

B: m

C: m%

D: m

Ans:

%. !f a body moves in such a way that its velocity increases by eual amount in eual intervals of time" it is said

to be moving with

A: a uniform retardation

B: a uniform acceleration

C: a variable acceleration

D: a variable retardation

Ans: 0


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. !f the gravitational accelerational at any place is doubled" the weight of a body" will

A: be reduced to half

B: be doubled

C: not be affected

D: none of these.

Ans: B

,. A particle moves along a straight line such that distance x traversed in t seconds is given by x = t (t E 1)" the

acceleration of the particle" will be

A: %t % ' t

B: %t E t

C: -t '

D: -t E

Ans:0

-. *he aw of $olygon of &orces states that

A: if a polygen representing the forces acting at point in a body is closed" the forces are in euilibrium

B:

if forces acting on a point can be represented in magnitde and direction by the sides of a polygon ta#en in

order" then the resultant of the forces will be represented in magnitude and direction by the closing side of the polygon

C:

if forces acting on a point can be represented of a polygon ta#en in order" their sides of a polygon ta#en in

order" their resultant will be represented in magnitude and direction by the closing side of the polygon" ta#en

in opposite order

D:if forces acting on a point can be represented in magnitude and direction by the sides of a polygon in order"

the forces are in euilibrium.


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Ans: 0

. $arallelogram aw of &orces states" Gif two forces acting simultaneously on a particle be represented in

magnitude and direction by two adacent sides of a parallelogram" their resultant may be represented in

magnitude and direction by

A: its longer sideG

B: its shorter sideG

C: the diagonal of the parallelogram which does not pass through the point of intersection of the forcesG

D: the diagonal of the parallelogram which passes through the point of intersection of the forcesG

Ans:

3. Which one of the following statements is true ?

A: *he tangent of the angle of friction is eual to coefficeint of friction

B: *he angle of repose is eual to angle of friction

C: *he tangent of the angle of repose is eual to coefficient of friction

D: All the above.

Ans:

5. *he product of mass and velocity of a moving a body" is called

A: moment

B: momentum

C: power


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D: impulse.

Ans: B

,8. DngineerHs units of force" is

A: +ewton in absolute units

B: yne in absolute units

C: +ewton and dyne in absolute units

D: All the above.

Ans: A

,1. Ioule is the unit of

A:wor# B:force 0:power :torue Ans: A

,. ne +ewton force" is

A: 18% dynes

B: 18 dynes

C: 18, dynes

D: 18- dynes

Ans: 0

,%. *he angle which an inclined surface ma#es with the horiontal when a body placed on it is on the point of

moving down" is called

A: angle of repose


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B: angle of friction

C: angle of inclination

D: none of these.

Ans:A

,. Wor# may be defined as

A: force 6 distance

B: force 6 velocity

C: force 6 acceleration

D: none of these.

Ans : A

,,. A bullet weighing 88 g is fired hori2ontally with a velocity of , m7sec from a gun carried on a carriage

which together with the gun weighs 188 #g. *he velocity of recoil of the gun" will be

A: 8.81 m7sec

B: 8.8, m7sec

C: 1.88 m7sec

D: 1., m7see.

Ans:B

,-. A satellite moves in its orbit around the earth due to


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A: ravitational force

B: 0entripetal force

C: 0entrifugal force

D: none of these.

Ans: B

,. !f g 1 and g are the gravitational accelerations on two mountains A and B respectively" the weight of a body

when transported from A to B will be multiplied by

A: g 1

B: g

C:

D:

Ans:

,3. When a body in euilibrium undergoes an infinitely small displacement" wor# imagined to be done" is #nown

as

A: imaginary wor#

B: negative wor#

C: virtual wor#

D: none of these.

Ans: 0


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,5. *he resultant of two forces P and Q acting at an angle J" is

A: P E Q E P sin J

B: P E Q E PQ cos J

C: P E Q E PQ tan J

D:

Ans:

-8. *he total time of collision and restitution of two bodies" is called

A: time of collision

B: period of collision

C: period of impact

D: all the above.

Ans:

-1. *he length of a @econdHs pendulum" is

A: 55.8 cm

B: 55. cm

C: 188 cm

D: 181 cm

Ans: B


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-. Ca6imum efficiency of a screw ac# for the angle of friction K" is

A:

B:

C:

D:

-%. u1 and u are the velocities of approach of two moving bodies in the same direction and their corresponding

velocities of separation are v1 and v. As per +ewtonHs law of collision of elastic bodies" the coefficient of

restitution (e) is given by

A:

B:

C:

D:

Ans: 0

-. *he c.g. of a thin hollow cone of height h" above its base lies on the a6is" at a height of

A:

B:

C:

D:

Ans: 0


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-,. *he 0.. of a right circular cone lies on its a6is of symmetry at a height of

A: h7

B: h7%

C: h7

D: h7,

Ans: 0

--. !f a particle is proected inside a hori2ontal tunnel which is ,, cm high with a velocity of -8 m per sec" the

angle of proection for ma6imum range" is

A: 39

B: 59

C: 189

D: 119

Ans:0

-. Dffect of a force on a body depends upon its

A: direction

B: magnitude

C: position

D: all the above.


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Ans:

-3. *he ratio of the reactions R A and R B of a simply supported beam shown in below figure is

A: 8.,8

B: 8.8

C: 8.-

D: 1.88

Ans:

-5. Which one of the following laws is not applicable to a simple pendulum ?.

A: *he time period does not depend on its magnitude

B: *he time period is proportional to its length l

C: *he time period is proportional to l where l is length

D: *he time period is inversely proportional to g where g is the acceleration due to gravity.

Ans:B

8. A body is said to move with @imple Larmonic Cotion if its acceleration" is

A: always directed away from the centre" the point of reference

B:

proportional to the suare of the distance from the point of reference


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C: proportional to the distance from the point of reference and directed towards it

D: inversely proportion to the distance from the point of reference

Ans: 0

1. *wo forces of - +ewtons and 3 +ewtons which are acting at right angles to each other" will have a resultant

of

A: , +ewtons

B: 3 +ewtons

C: 18 +ewtons

D: 1 +ewtons

Ans: 0

. +ewtonHs law of 0ollision of elastic bodies states that when two moving bodies collide each other" theirvelocity of separation

A: is directly proportional to their velocity of approach

B: is inversely proportional to their velocity of approach

C: bears a constant ratio to their velocity of approach

D: is eual to the sum of their velocities of approach.

Ans: 0

3. !f F and u are the angle of proection and initial velocity of a proectile respectively" the hori2ontal range of

the proectile" is


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A:

B:

C:

D:

Ans: A

5. C.!. of a thin ring (e6ternal diameter D" internal diameter d ) about an a6is perpendicular to the plane of the

ring" is

A:( D E d )

B:( D ' d )

C:( D E d )

D:( D 6 d ).

Ans: B

38. &or ma6imum range of a proectile" the angle of proection should be

A: %89

B: ,9

C: -89

D: none of these.

Ans: B


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31. *he ratio of the ranges on the inclined plane with motion upward and with motion downward for a given

velocity" angle of proection will be

A:

B:

C:

D:

Ans: B

3. A @econds pendulum e6ecutes

A: 8., beat per second

B: 1.8 beat per second

C: .8 beats per second

D: ., beats per second

Ans: 0

3%. *he resultant of the forces acting on a body will be 2ero if the body

A: rotates

B: moves with variable velocity in a straight line

C: moves along a curved path

D: does not move at all.


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Ans:

3. According to aw of *riangle of &orces

A:three forces acting at a point" can be rep'resented by the sides of a triangle" each side being in proportion tothe force

B: three forces acting along the sides of a triangle are always in euilibrium

C:if three forces acting on a" point can be represented.in magnitude and direction" by the sides of a triangle

ta#en in order" these will be in euilibrium

D:

if the forces acting on a particle be represented in magnitude and direction by the two sides of a triangle

ta#en in order" their resultant will be represented in magnitude and direction by the third side of the triangle"

ta#en in opposite order.

Ans:

3,. *he following is not a law of static friction :

A: *he force of friction always acts in a direction opposite to that in which the body tends to move

B: *he force of friction is dependent upon the area of contact

C: *he force of friction depends upon the roughness of the surface

D: *he magnitude of the limiting friction bears a constant ratio to the normal reaction between two surfaces.

Ans: A

3-. *he velocity of a moving body" is

A: a vector uantity

B: a scalar uantity

C: a scalar as well as a vector uantity

D:

none of these.


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Ans: A

3. *he resolved part of the resultant of two forces inclined at an angle J in a given direction is

A: algebraic sum of the resolved parts of the forces in the direction

B: arithmetical sum of the resolved parts of the forces in the direction

C: difference of the forces multiplied by cosine J9

D: sum of the forces multiplied by the sine J

Ans:A

33. !f two forces acting at a point are in euilibrium" they must be eual in magnitude and their line of action

must be along

A: the same line in the same sense

B: the same line in opposite sense

C: the perpendicular to both the lines

D: none of these.

Ans: B

35. !f two forces P and Q ( P M Q) act on the same straight line but in opposite direction" their resultant" is

A: P E Q

B:

P 7Q


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C: Q7 P

D: P ' Q

Ans:

58. !f the angle between the applied force and the direction of motion of a body" is between 589 and 1389" the

wor# done" is called

A: virtual wor#

B: imaginary wor#

C: 2ero wor#

D: negative wor#.

Ans:

51. *he units of moment of inertia of an area" are

A: #g7m

B: #g7m

C: m

D: m%

Ans:0

5. &or a body moving with simple harmonic motion" the number of cycles per second" is #nown as its


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A: oscillation

B: amplitude

C: periodic time

D: freuency.

Ans:

5%. !f the hori2ontal range is ., times the greatest height" the angle of proection of the proectile" is

A: ,9

B: ,39

C: ,59

D: -89.

Ans: B

5. *ime reuired to stop a car moving with a velocity 8 m7sec within a distance of 8 m" is

A: sec

B: % sec

C: sec

D: , sec

Ans: 0

5,. *he characteristic of a couple" is :


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A: algebraic sum of forces" constituting a couple is 2ero

B: algebraic sum of moments of forces" constituting a couple" about any poin" is same

C: a couple can be balanced only by a couple but of opposite sense

D: all the above.

Ans:

5-. *he inherent property of a body which offers reluctance to change its state of rest or uniform motion" is

A: weight

B: mass

C: interia

D: momentum.

Ans: 0

5. &or a simple pendulum" the period of one oscillation is

A: Nl 7 g

B: N g 7l

C: Nl 7 g

D: N g 7l .

Ans: 0

53. *he angle of friction is :


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A: *he ratio of the friction and the normal reaction

B: *he force of friction when the body is in motion

C: *he angle between the normal reaction and the resultant of normal raction and limiting friction

D: *he force of friction at which the body is ust about to move.

A+s: 0

55. *he motion of a particle is described by the relation x = t ' 18t E %8" where x is in metres and t in seconds.

*he total distance travelled by the particle from t = 8 to t = 18 seconds would be

A: 2ero

B: %8 m

C: ,8 m

D: -8 m

Ans: A

188. *hree forces which act on a rigid body to #eep it in euilibrium. *he forces must be coplanar and

A: concurrent

B: parallel

C: concurrent parallel

D: none of these.

Ans: A


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181. &or perfectly elastic bodies" the value of coefficient of restitution is

A: 2ero

B: 8.,

C: 1.8

D: between 8 and 1.

Ans: 0

18. Which of the following do not have identical dimensions ?

(a) Comentum and impulse

(b) *orue and energy

(c) *orue and wor#

(d) Oinetic energy and potential energy

(e) Coment of a force and angular momentum.

Ans: e

18%. *he resolved part of the resultant of two forces inclined at an angle 5 in a given direction is eual to

(a) the algebraic sum of the resolved parts of the forces in the given direction

(b) the sum of the resolved parts of the forces in the given direction

(c) the difference of the forces multiplied by the cosine of 5

(d) the sum of the forces multiplied by the sine of 5

(e) the sum of the forces multiplied by the tangent of 5.

Ans: a

18. *he algebraic sum of the resolved parts of a number of forces in a given direction is eual to the resolved

part of their resultant in the same direction. *his is as per the principle of

(a) forces

(b) independence of forces

(c) dependence of forces

(d) balance of force

(e) resolution of forces.

Ans: e

18,. !f two eual forces of magnitude $ act at an angle 59" their resultant will be

(a) $7 cos 57

(b) !$ sin 57

(c) $ tan 57


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(d) !$ cos 57

(e) $sin 57.

Ans: d

18-. A force is completely defined when we specify

(a) magnitude

(b) direction(c) point of application

(d) all of the above

(e) none of the above.

Ans: d

18. !f a number of forces act simultaneously on a particle" it is possible

(a) not a replace them by a single force

(b) to replace them by a single force

(c) to replace them by a single force through 0..

(d) to replace them by a couple

(e) to replace them by a couple and a force.

Ans: b

183. Dffect of a force on a body depends upon

(a) magnitude

(b) direction

(c) position or line of action

(d) all of the above


Ans: d

185. Which is the correct statement about law of polygon of forces ?

(a) if any number of forces acting at a point can be represented by the sides

of a polygon ta#en in order" then the forces are in euilibrium

(b) if any number of forces acting at a point can be represented in direction and magnitude by the sides of a

polygon" then the forces are in euilibrium

(c) if a polygon representing forces acting at a point is closed then forces are in euilibrium

(d) if any number of forces acting at a point can be represented in direction and magnitude by the sides of a

polygon ta#en in order" then the forces are in euilibrium


Ans: d

118. A force acting on a body may

(a) introduce internal stresses

(b) balance the other forces acting on it

(c) retard its motion

(d) change its motion


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(e) all of the above.

Ans: e

111. &orces are called coplanar when all of them acting on body lie in

(a) one point

(b) one plane

(c) different planes(d) perpendicular planes

(e) different points.

Ans: b

11. &orces are called concurrent when their lines of action meet in

(a) one point

(b) two points

(c) plane

(d) perpendicular planes

(e) different planes.

Ans: a

11%. *he unit of wor# or energy in @.!. units is

(a) newton

(b) pascal

(c) #ilogram meter

(d) watt

(e) oule.

Ans: e

11. *he unit of force in @.!. units is

(a) #ilogram

(b) newton

(c) watt

(d) dyne

(e) oule.

Ans: b

C4*!$D 0L!0D P4D@*!+@

1. A body let fall from the top of a building reaches the ground in 3 s. The height of th

building is:

a. 14.7 m b. 29.4 m c. 44.1 m d. 66.2 m


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2. A bomb is released by a horiontally !ying aeroplane. The tra"ectory of the bomb is a:

a. #traight line b. $arabola c. %yperbola d. &ircle

3. The property of a body due to 'hich it resists any change in its state of rest or of uniform

translatory motion is called its:

a. (ass b. )eight c. *nertia d. (oment of inertia

4. )hich of the follo'ing graphs represents motion 'ith uniform +elocity:

t

s

t

s

t

a

t

a

a b c d

,. A cannon ball has the same range R on a horiontal plane for t'o angles of pro"ection.

h1 and h2 are the greatest heights in the t'o paths for 'hich this is possible- then:

a. R = h1h2 b.1

) hh R =

c.

%1hh R =

d.

( ) )1

1hh R =

6. T'o bodies of masses 1 /g and , /g are mo+ing in concentric orbits of radii r 1 and r 2 suc

that their periods are same. The ratio of centripetal accelerations is:

a.1

7 r r

b.1

7 r r

c.

( ) %1 7 r r d.

( ) 1 7 r r

7. A particle is mo+ing on a circle 'ith uniform speed0 its motion is:

a. periodic and simple harmonic b. periodic but not simple harmonic

c. periodic d. none of the abo+e

. The x and y coordinates of a particle at any time t are gi+en by: x 7t 4t 2 and y = ,t, 'here x and y are in m and t in s.


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The acceleration of the particle at , s is:

a. 5ero b. ms2 c. 2 ms2 d. 4 ms2

9. A bullet 'eighing , g lea+es the gun 'ith a +elocity of 3 ms. *f the recoil speeimparted to the gun is 1 ms- the mass of the gun:a. 1, /g b. 3 /g c. 1., /g d. 2 /g

1. )hen a steady torue or couple acts on a body- the body:a. &ontinues in a state of rest or of uniform motion by 8e'tons rst la'

b. ;ets linear acceleration by 8e'tons ** la'

c. &ontinues to rotate at a steady rate

d. ;ets an angular acceleration

11. A force of one 8e'ton acts on a body of mass 1 /g. *t 'ill produce in the body:a. An acceleration of 1 cms2 b. A +elocity of 1 ms

c. An acceleration of 9 cms2 d. A +elocity of 9 cms

12. The #* unit of temperature is:a.


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T1

T2

T3

1/g

2/g

3/g

a.r 7

υ b.

r υ c.

r 7υ d.

υ 7r

1. A particle starts from rest and mo+es 'ith an acceleration a 'hich +aries 'ith timaccording to the euation a = kt - 'here k is a constant. The displacement S ofparticle at time t is:

a.

1kt

b.

1

at c.

-

1

at d.

%kt

19. )hen a mango tree is sha/en mangoes are detached from the tree branchesbecause:

a. There is no option to them eCcept to fall do'n

b. (angoes eCperience a net do'n'ard pull to'ards ground

c. (angoes tend to continue in a state of rest and branches go into motion

d. Dranches tend to continue in the state of rest and the mangoes go in motion

20. *f a body A of mass M is thro'n 'ith +elocity v at an angle 3E to the horioanother body B of same mass is thro'n at an angle of 6E to the horiontal the range of A and B 'ill be:

a.%:1

b.%

: 1 c. 1 : 3 d. 1 : 1

The distance mo+ed by a freely falling body starting from restB during 1st- 2nd- 3rd- . . . nth s of its motion are proportional to:

a. @+en numbers b. Fdd numbers

c. All integral numbers d. #uare of integral numbers

A body falling under gra+ity mo+es 'ith uniform:a. #peed b. Gelocity

c. (omentum d. Acceleration

A bullet in motion hits and gets embedded in a solid bloc/ resting on a frictionlestable.)hat is conser+edH

a. (omentum and =@ b. =inetic energy alone

c. 8either =@ nor momentum d. (omentum alone

A surface is hit elastically and normally by n balls per unit time- all the balls ha+ing thsame mass m and mo+ing 'ith the same +elocity u. The force on the surface is:

a. mnu2 b. 2 mnu

c. 12B mnu2 d. 2 mnu2


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>ind the tension T 2 in the system sho'n in >ig.a. 1g 8 b. 2g 8

c. ,g 8 d. 8one

)hat is the unit of measurement used to calculate domestic consumption of electricity:a. "oule b. +olt c. /)h d. 'att

27. The unit of impulse is the same as that of:a. @nergy b. >orce

c. Angular momentum d. Iinear momentum

2. @ssential characteristic of euilibrium is:a. (omentum euals ero b. Acceleration euals ero

c. =.@. euals ero d. Gelocity euals ero

29. A bomb of mass 9 /g eCplodes into t'o pieces of masses 3 /g and 6 /g. Th+elocity of mass 3 /g is 16ms. The =@ of mass 6 /g in "oule is:a. 96 b. 34 c. 192 d. 76

3. )or/ing of roc/et or "et is based on:a. 8e'tons * la' b. 8e'tons ** la'

c. 8e'tons *** la' d. All the three la's

31. )hat happens to the centripetal acceleration of a re+ol+ing body if you double thorbital speed and hal+e the angular +elocity:

a. Jemains unchanged b. *s hal+ed

c.


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+ +t

+

t

+

34. A sphere of mass m mo+ing 'ith a constant +elocity u hits another stationarsphere of the same mass. *f e is the coeLcient of restitution- then ratio of +elocities othe t'o spheres after collision 'ill be:

a.

+−e

e

1

1

b.

=+e

e

1

1

c.

−+1

1

e

e

d.

+−1

1

e

e

3,. The +elocity of a body depends on time according to the euation M = 2 .1t 2

The body is undergoing:a. Nniform acceleration b. Nniform retardation

c. 8onuniform acceleration d. 5ero acceleration

36. A man can thro' a stone m. The maCimum height to 'hich it 'ill rise in metreis:

a. 1 b. 2 c. 4 d. ,

37. The re+ol+er recoils after a bullet is red because:

a. The man dra's it bac/'ards out of fear

b. The trigger of the re+ol+er mo+es bac/'ards

c. The for'ard motion of the bullet imparts to the re+ol+er an eual and

opposite reaction

d. The uestion is irrele+ant

3. )hich of the follo'ing gures represents the motion of a body mo+ing in a straighlineunder constant acceleration:

a. b. c. d.

39. The angular speed of the seconds hand of a cloc/ is:

a.

( ) srad 7-871

b.

( ) srad 7-87π

c.

( ) srad 7-87π d.

( ) srad 7-87%-8

4. A body is mo+ing in a circular path 'ith a constant speed0 its acceleration acts in direction:

a.Along the tangent

t

t


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b.Along the circumference

c.Along the radius to'ards the centre

d.Along the radius a'ay from the centre

41. Angular momentum of a body is dened as the product of:

a. (ass and angular +elocity b. &entripetal force and radius

c. Iinear +elocity and angular +elocity

d. (oment of inertia and angular +elocity

42. The displacement of a particle eCecuting #%( is gi+en by x .1 sin 1π

t .,B. The time period is:

a. .1 sec b. .2 sec c. .1 sec d. .2 sec

43. The #* unit of pressure is:a. atmosphere b. bar c. $ascal d. mm of %g

44. A bloc/ of mass 2 /g is placed on the !oor. The coeLcient of static friction is .4. a force

of 2. 8 is applied on the bloc/ parallel to !oor the force of friction bet'een the

bloc/ and

!oor ta/en g 1 ms2B is:

a. 2. 8 b. 8 c. 2 8 d. 5ero

4,. A motorist tra+els from A to B at a speed of 4 /mhr and returns bac/ at a speed o6 /mhr. %is a+erage speed 'ill be:

a. 4 /mhr b. 4 /mhr c. , /mhr d. 6 /mhr

46. A ball is released from the top of height h metre. *t ta/es T second to reach thground.

)here is the ball at the time T 2 sec:

a. At h/ 4B m from the ground b. At h/ 2B m from the ground

c. At 3h/ 4B m from the ground d.


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a.

( )φ θ φ −cos7cosW b.

( )φ θ φ +cos7sinW

c.

( )φ θ φ −sin7tanW d.

( )φ θ θ −tan7sin g W

4. The initial +elocity of a particle mo+ing along a straight line is 1 ms and it

retardation is 2ms2. The distance mo+ed by the particle in the fth sec. of its motion is:

a. 1 m b. 19 m c. , m d. 7, m

49. The shaft of a motor rotates at a constant angular +elocity of 3J$(. The radianit has tuned in 1 sec are:

a.π 1888

b.π 188

c.π

d.π 18

,. A ri!e bullet loses

th

8

1

of its +elocity in passing through a plan/. >ind ho' mansuch uniform plan/s it 'ould pass through before coming to rest assuming resistancto the plan/ to be uniform:

a. 2 b. 11 c. 12 d. 1

,1. The type of motion 'hen acceleration is proportional to displacement but directedoppositely is called:

a. translatory b. rotatory c. gyroscopic d. simple harmonic

,2. T'o particles of eual masses are re+ol+ing in circular paths of radii r 1and r

respecti+ely 'ith the same speed. The ration of their centripetal force is:

a.1

7 r r

b.1

7 r r

c.

( ) 1 7 r r d.

( ) 1 7 r r

53. The x and y displacements of a particle in the xy plane at any instant are gi+en b x = aT 2 and 2aT 'here a is a constant. The +elocity of the particle at any instant igi+en by:

a.

)) +T a

b.

1 +T a

c.

1) +T a

d.

)

+T a

,4. )hen the +elocity of a body is doubled:a. *ts momentum is doubled b. *ts =@ is doubled

c. *ts $@ is doubled d. *ts acceleration is doubled

,,. Fne micron is:


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a. 19 m b. 112 m c. 16 m d. 11, m

,6. A ball is thro'n up'ards and returns to the ground describing a parabolic path)hich of the follo'ing uantities remains constant:

a. =inetic energy of the ball b. The speed of the ball

c. The +ertical component of +elocity

d. The horiontal component of +elocity

,7. T'o balls at the same temperature collide 'hich is conser+ed:a. Temperature b. Gelocity c. =inetic energy d. (omentum

,. orce b. )or/ c. (omentum d. Angular momentum

,9. A body of mass 2 /g rests on a rough inclined plane ma/ing an angle 3E 'ith thhoriontal. The coeLcient of static friction bet'een the bloc/ and the plane is .7. Thfrictional force on the bloc/ is:

a. 9. 8 b. .7 C 9. C%

8 c. 9. C%

8 d. .7 C 9. 8

6. A person tra+els along a straight road for the rst half length 'ith a constant speeM1 and the second half length 'ith a constant speed M2. The a+erage speed ! is:

a. M1 " M2B2 b. 2 M1 M2 M1 M2B c. M1 M2B12 d. M2 M1B

12

61. The displacement # of a point mo+ing in a straight line is gi+en by: # = t 2 " 3t $ ,# being in cm and t in #. The initial +elocity of the particle is:

a. 3 cms b. 16 cms c. 19 cms d. 5ero

62. A particle is pro"ected at angle of 4,E 'ith a +elocity of 9. ms.The horiontal rang'ill be:

a. 9. m b. 4.9 m c. 9.

m d. 9.

m

63. )ith 'hat speed should a body be thro'n up'ards so that the distances tra+ersein the ,th second and 6th second are eual:

a. ,.4 ms b. 49 ms c. 9 ms d.53

ms

64. *f a body A of mass M is thro'n 'ith +elocity v at an angle 3E to the horiontal ananother body B of same mass is thro'n at an angle of 6E to the horiontal the ratio orange of A and B 'ill be:

a.%:1

b.%

: 1 c. 1 : 3 d. 1 : 1

6,. At 'hat angle to the horiontal should an ob"ect be pro"ected so that the maCimumheight reached is eual to the horiontal range:


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a. tan O 2 b. tan O 4 c. tan O 23 d. O 3

66. T'o bodies of diPerent masses ma and m% are dropped from t'o diPerent heights+i0 a and %. The ratio of time ta/en by the t'o to drop through these distances is:

a. a : % b. ma /m% : %/a c.a

:b

d. a2 : %2

67. A stone is thro'n +ertically up'ards 'ith a +elocity of 9 ms. *ts +elocity 'ill bero after g 9. ms2B:

a. 14 s b. 1 s c. 2 s d. , s

6. A stone is dropped into a la/e from a to'er , m high. The sound of the splash 'be heard by a man on the to'er after:

a. 21 s b. 1 s c. 11., s d. 14 s

69. 8e'tons ** la' of motion connects:a. (omentum and acceleration b. &hange of momentum and +elocity

c. Jate of change of force and momentum

d. Jate of change of force and momentum

7. The +elocity ver#u# time cur+e of a mo+ing point is sho'n belo'. The retardation isa. 1 cmsec2 b. 2 cm sec2 c. 3 cmse2 d. 4 cmsec2

. 1. 2. 3. 4. ,. 6. 7.

G

T

6.

2.

71. A motor cyclist going round in a circular trac/ at const. #peed has:a.&onstant acceleration b.&onstant +elocity

c.Acceleration of constant magnitude 'ith its direction changing

d.&onstant force

72. Jail'ay trac/s are ban/ed at the cur+es so that:a. The train may not fall do'n in'ards


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b. The 'eight of the train may be reduced

c. The necessary centripetal force may be obtained from the horiontal componen

of the reaction of the train.

d. 8o frictional force may be produced bet'een the 'heel and the trac/

73. (oment of momentum is called:a. *nertia b. (oment of inertia c. Torue d. Angular momentum

&'. A simple harmonic motion ha+ing amplitude A and T is represented by the en: y

, sin

( ))+t π m

Then the +alues of A in mB and T in sB are:

a. A ,0 T 2 b. A 10 T 1 c. A ,0 T 1 d. A 10 T 2

7,. The =@ and $@ of a particle eCecuting #%( 'ith amplitude A 'ill be eual 'hen its

displacement is:

a. A

b.7 A

c.7 A

d.%7 A

76. =@ of a body of mass m and momentum (- is gi+en by:a. m( b. (22mB c. (2m d. m22 (B

77. A body starting from rest co+ers a distance of 9 m in the fth second. Thacceleration of the body is:

a. 2 ms2 b. .2 ms2 c. 1. ms2 d. 4 ms2

7. )hen t'o bodies collide elastically- then:a. =@ of the system alone is conser+ed

b. Fnly momentum is conser+ed

c. Doth =@ and momentum are conser+ed

d. 8either =@ nor momentum is conser+ed

79. A light and a hea+y body ha+e eual momentum. )hich one has greater /inetienergyH

a. The light body b. The hea+y body

c. Doth ha+e eual =@ d. 8othing can be said

. %ert is a unit of:a. @lectromagnetic energy b. >reuency

c. @lectric eld strength d. (agnetic permeability


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1. Fne /ilo'atthour is eual to:a. 3.6 C 16 "oule b. 3.6 C 1, "oule c. 13 "oule d. 17 "oule

2. A gi+en mass of a metal is moulded into solids of diPerent shapes. *ts surface areis minimum 'hen it is

a. A right circular cylinder b. A spheroid

c. A paraboloid of re+olution c. A right circular cone

3. Fne nanometer is eual to:a. 19 mm b. 16 cm c. 17 cm d. 19 cm

4. )hich of the follo'ing is not the unit of length:a. micron b. light year c. anstrom d. radian

,. >or a particle mo+ing under the action of a central force elda. its angular momentum is conser+ed

b. its angular momentum increases

c. its angular momentum decreases

d. the path is al'ays linear.

6. >orces are called coplanar 'hen all of them acting on body lie inaB one point bB one plane cB diPerent planes

dB perpendicular planes

7. The resol+ed part of the resultant of t'o forces inclined at an angle O in a gi+endirection is eual to

aBthe algebraic sum of the resol+ed parts of the forces in the gi+en directionbBthe sum of the resol+ed parts of the forces in the gi+en directioncB the difference of the forces multiplied by the cosine of OdBthe sum of the forces multiplied by the sin of O the sum of the forces multiplied

by the tangent of )hen trying to turn a /ey into a loc/- follo'ing is applied

aB coplanar forcebB noncoplanar forces cB le+er dB couple

9. According to la' of triangle of forces

aB three forces acting at a point 'ill be in euilibrium

bB three forces acting at a point can be represented by a triangle- each side being

proportional to force


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cB if three forces acting upon a particle are represented in magnitude and directio

by the sides of triangle- ta/e in order- they 'ill be in euilibrium

dB if three forces acting at a point are in euilibrium- each force is proportional t

the sine of the angle bet'een the other t'o.

9. According to Iamis theorem

aB three forces acting at a point 'ill be in euilibriumbB three forces acting at a

point can be represented by a triangle- each side being proportional to force cB if

three forces acting upon a particle are represented in magnitude and direction by

the sides of a triangle- ta/en in order- they 'ill be in euilibrium dB if three forces

acting at a point are in euilibrium

91. A framed structure is perfect if it contains members eual to

aB 2" Q3 bB" Q 1 cB 2" Q 1 dB " Q 2

'here " number of "oints in a frame

92. *n determining stresses in frames by methods of sections- the frames is di+ided into

t'o parts by an imaginary section dra'n in such a 'ay as not to cut more than

aB t'o members 'ith un/no'n forces of the frame

bB three members 'ith un/no'n forces of the frame .

cB four members 'ith un/no'n forces of the frame

dB three members 'ith /no'n forces of the frame

93. &enter of gra+ity of a solid cone lies on the aCis at the height

aB one Q fourth of the total height abo+e base

bB one Q third of the total height abo+e base

cB one Q half of the total height abo+e base

dB threeeight of the total height abo+e base

94. The units of moment of inertia of an area are

aB /g m2 bB m4 cB /gm2 dB m3

9,. (.* of a thin circular ring of radius r and mass ( about an aCis perpendicular to

plane of ring is

aB (r2 bB Rr4 2 cB 2, (r2 dB 23 (r2


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96. (.* of a circular area about an aCis perpendicular to the area is

aB (r2 bB Rr4 2 cB 2, (r2 dB 23 (r2

5. *he C.! of a thin ring" e6ternal diameter " internal diameter d" about an a6is perpendicular to the plane

of the ring isaB R 64 or maCimum range of a pro"ectile- the angle of pro"ection should be

aB 3 bB 4, cB 6 dB 36

13. &oloumb friction is the friction bet'een

aB bodies ha+ing relati+e motion bB t'o dry surfaces

cB t'o lubricated surfaces dB solids and liuids

14.


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1,. The &.; of a solid hemisphere lies on the central radius

aB at distance 3r2 from the plane base

bB at distance 3r4 from the plane base

cB at distance 3r, from the plane base

dB at distance 3r from the plane base

18-. Coment of inertia of a circular area" whose diameter is d" about an a6is perpendicular to the area" passing

through its centre is given by

aB πd464 bB πd4 32 cB πd4 12 dB πd4 16

17. A ball is thro'n up. The sum of /inetic and potential energies 'ill be maCimum at

aB ground bB highest point cB in the center 'hile going up

dB at all the points

1. Fne 8e'ton is eual to

aB 17 dyne bB 1, cB 14 dyne dB 13 dyne

19. The angular +elocity of a particle changes from 69 to 71 rpm in 3 secs. *ts angular

acceleration in re+min is eual to

aB 1 bB 2 cB 4 dB

11. A body of mass m mo+ing 'ith a constant +elocity + hits another body of same

mass at rest and stic/s to it. The +elocity of both together 'ill be eual to

aB U bB 5ero cB 2 U dB U 2

111. Jate of change of momentum ta/es place in the direction

aB of motion bB of applied force

cB opposite to the direction of applied force

dB perpendicular to the direction of motion

112. *f a solid and a hollo' sphere of the same mass are allo'ed to roll do'n an inclinedplane simultaneously- then

aB solid sphere 'ill reach the ground rst bB hollo' sphere 'ill reach the

ground rst

bB both 'ill reach the ground at same time cB unpredictable


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113A !y'heel starting from rest and accelerating uniformly performs 2, re+olutions in

, sec. *ts angular +elocity in rpm after 1 seconds 'ould be

AB 2 rpm DB 2, rpm

&B 4, rpm


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&B 3 8


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Engineering Mechanics objective

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