asportzone.com – MCQs, Mock Tests | IIT JEE Mechanical Engineering Engineering Mechanics Part 1

1 20. The weight of a body is due tocgravitational pull exerted by the earth

A centripetal force of earth B forces experienced by body in atmos-phere C force of attraction experienced by par-ticles D gravitational force of attraction towards the centre of the earth.

✅ Correct Answer: 4

2 The magnitude of two forces which when acting at right angle produce resultant force of VlOkg and when acting at 60? produce resultant of Vl3 kg. These forces are

A 2 and V6 B 2 and 5 C V5andV5 D none of the above.

✅ Correct Answer: 3

3 Forces are called concurrent when their lines of action meet in

A one point B two points C plane D perpendicular planes

✅ Correct Answer: 1

4 Which of the following is not the unit of pressure ?kg/cm

A kg/cm B ata C atmosphere D newton

✅ Correct Answer: 4

5 18. Which of the following is not the unit of work energy and heat ?

A kcal B kg m C kWhr D hp

✅ Correct Answer: 4

6 Forces are called coplanar when all of them acting on body lie in

A one point B one plane C different planes D perpendicular planes

✅ Correct Answer: 2

7 Which of the following is not the unit of power ?kg m/sec

A kW (kilowatt) B hp (horse power) C kcal/sec D kcal/kg sec.

✅ Correct Answer: 4

8 Which of the following do not have identical dimensions ?Kinetic energy and potential energy

A Momentum and impulse B Torque and energy C Torque and work D Moment of a force and angular momentum.

✅ Correct Answer: 4

9 The unit of work or energy in S.I. units iswatt

A newton B pascal C kilogram metre D joule.

✅ Correct Answer: 4

10 The unit of power in S.I. units is

A newton metre B watt C joule D kilogram metre/sec.

✅ Correct Answer: 2

11 Which of the following is not the unit of distance ?millimetre

A angstrom B light year C micron D milestone.

✅ Correct Answer: 4

12 Effect of a force on a body depends upon

A magnitude B direction C position or line of action D all of the above

✅ Correct Answer: 4

13 A force acting on a body maybalance the other forces acting on itretard its motion

A introduce internal stresses B balance the other forces acting on itretard its motion C change its motion D all of the above.

✅ Correct Answer: 4

14 Which of the following is a vector quantityenergy

A energy B mass C momentum D angle

✅ Correct Answer: 3

15 A force is completely defined when we specifyall of the abovenone of the above.

A magnitude B direction C point of application D all of the above.

✅ Correct Answer: 4

16 When trying to turn a key into a lock following is appliedmoment

A coplanar force B non-coplanar forceslever C moment D couple.

✅ Correct Answer: 4

17 The forces which meet at one point but their lines of action do not lie in a plane are called

A coplanar non-concurrent forces B non-coplanar concurrent forces C non-coplanar non-concurrent forces D intersecting forces

✅ Correct Answer: 2

18 The algebraic sum of the resolved parts of a number of forces in a given direction is equal to the resolved part of their resultant in the same direction. This is as per the principle ofbalance of force

A forces B independence of forces C dependence of forces D resolution of forces.

✅ Correct Answer: 4

19 If two equal forces of magnitude P act at an angle 9? their resultant will be

A P/2 cos 9/2 B IP sin 9/2 C 2P tan 9/2 D IP cos 9/2

✅ Correct Answer: 2

20 Which of the following is not a scalar quantityvolumeacceleration.

A time B mass C volume D density

✅ Correct Answer: 4

21 If a number of forces act simultaneously on a particle it is possibleto replace them by a couple and a force.

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 C.G. D to replace them by a couple

✅ Correct Answer: 2

22 According to principle of transmissibility of forces the effect of a force upon a body isnone of the above.

A maximum when it acts at the centre of gravity of a body B different at different points in its line of action C the same at every point in its line of action D minimum when it acts at the C.G. of the body

✅ Correct Answer: 3

23 The resolved part of the resultant of two forces inclined at an angle 9 in a given direction is equal tothe sum of the forces multiplied by the tangent of 9.

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 9 D the sum of the forces multiplied by the sine of 9

✅ Correct Answer: 1

24 Centre of gravity of a thin hollow cone lies on the axis at a height ofone-fourth of the total height above basethree-eighth of the total height above the basenone of the above.

A one-fourth of the total height above base B one-third of the total height above base C one-half of the total height above base D

✅ Correct Answer: 2

25 The product of either force of couple with the arm of the couple is calledresulting couplenone of the above.

A resultant couple B moment of the forces C resulting couple D moment of the couple

✅ Correct Answer: 4

26 From a circular plate of diameter 6 cm is cut out a circle whose diameter is a radius of the plate. Find the e.g. of the remainder from the centre of circular plate0.25 cm.

A 0.5 cm B 1.0 cm C 1.5 cm D 2.5 cm

✅ Correct Answer: 1

27 Centre of percussion isthe point of metacentrepoint of suspension

A the point of C.G. B the point of metacentre C the point of application of the resultant of all the forces D tending to cause a body to rotate about a certain axis

✅ Correct Answer: 3

28 In detennining stresses in frames by methods of sections the frame is divided into two parts by an imaginary section drawn in such a way as not to cut more thanfour members with two known forces.

A two members with unknown forces of the frame B three members with unknown forces of the frame C four members with unknown forces of the frame D three members with known forces of the frame

✅ Correct Answer: 2

29 Two non-collinear parallel equal forces acting in opposite direction

A balance each other B constitute a moment C constitute a couple D constitute a moment of couple

✅ Correct Answer: 3

30 The units of moment of inertia of an area are

A kg m2 B m4 C kg/m2 D m3

✅ Correct Answer: 2

31 A heavy string attached at two ends at same horizontal level and when central dip is very small approaches the following curve

A catenary B parabola C hyperbola D elliptical

✅ Correct Answer: 2

32 The possible loading in various members of framed structures are

A compression or tension B buckling or shear C shear or tension D all of the above

✅ Correct Answer: 1

33 The centre of gravity of a uniform lamina lies atall of the above

A the centre of heavy portion B the bottom surface C the mid point of its axis D none of the above.

✅ Correct Answer: 3

34 The units of moment of inertia of mass arem2/kg.

A kg m2 B m4 C kg/m2 D kg/m

✅ Correct Answer: 1

35 Centre of gravity of a solid cone lies on the axis at the height

A one-fourth of the total height above base B one-third of the total height above base C one-half of the total height above base D three-eighth of the total height above the base

✅ Correct Answer: 1

36 The centre of percussion of the homogeneous rod of length L suspended at the top will be3L/8.

A L/2 B L/3 C 3L/4 D 2L/3

✅ Correct Answer: 3

37 A trolley wire weighs 1.2 kg per metre length. The ends of the wire are attached to two poles 20 metres apart. If the horizontal tension is 1500 kg find the dip in the middle of the span

A 2.5 cm B 3.0 cm C 4.0 cm D 5.0 cm

✅ Correct Answer: 3

38 The centre of gravity of a triangle lies at the point of

A concurrence of the medians B intersection of its altitudes C intersection of bisector of angles D intersection of diagonals

✅ Correct Answer: 1

39 Which of the following is not a vector quantity

A weight B velocity C acceleration D force

✅ Correct Answer: 1

40 1# Which of the following is the locus of a point that moves in such a manner that its distance from a fixed point is equal to its distance from a fixed line multiplied by a constant greater than one

A ellipse B hyperbola C parabola D circle

✅ Correct Answer: 2

41 Which of the following is the example of lever of first order

A arm of man B pair of scissors C pair of clinical tongs D all of the above

✅ Correct Answer: 4

42 If three forces acting in different planes can be represented by a triangle these will be in

A non-equilibrium B partial equilibrium C full equilibrium D unpredictable

✅ Correct Answer: 1

43 The M.I. of hollow circular section about a central axis perpendicular to section as compared to its M.I. about horizontal axis is

A same B double C half D four times

✅ Correct Answer: 2

44 Which of the following is not the unit of energy

A kg m B kcal C wattr D watt hours

✅ Correct Answer: 4

45 The maximum frictional force which comes into play when a body just begins to slide over another surface is called

A limiting friction B sliding friction C rolling friction D kinematic friction

✅ Correct Answer: 1

46 A flywheel on a motor goes from rest to 1000 rpm in 6 sec. The number of revolutions made is nearly equal to

A 25 B 50 C 100 D 250

✅ Correct Answer: 2

47 The C.G. of a solid hemisphere lies on the central radius 3r

A at distance ? from the plane base 3r B at distance ? from the plane base 3r C at distance ? from the plane base 3r D at distance ? from the plane base or

✅ Correct Answer: 4

48 In the lever of third order load W effort P and fulcrum F are oriented as follows

A W between P and F B F between W and P C P between W and F D W P and F all on one side

✅ Correct Answer: 1

49 The algebraic sum of moments of the forces forming couple about any point in their plane is

A equal to the moment of the couple B constant C both of above are correct D both of above are wrong

✅ Correct Answer: 1

50 If n = number of members andy = number of joints then for a perfect frame n =

A j-2 B 2j-l C 2/-3 D 3/-2

✅ Correct Answer: 3

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Mechanical Engineering Engineering Mechanics Part 1