Category: Machine Kinematics Objective Questions

250+ TOP MCQs on Single Slider Crank Chain and its Inversions – 1 and Answers

Machine Kinematics Multiple Choice Questions on “Single Slider Crank Chain and its Inversions – 1”.

1. The quick return mechanism which is an inversion of 4-bar linkage is
a) Drag link mechanism
b) Whitworth quick return mechanism
c) Crank and slotted lever mechanism
d) None of the mentioned
Answer: a
Clarification: Drag link mechanism is an inversion of 4-bar linkage, which is a crank mechanism with different crank lengths. It is made up of revolute pairs only.

2. Match list I with list II
List I List II
A. Pantograph 1. Scotch yoke mechanism
B. Single slider crank 2. Double lever mechanism
C. Double slider crank chain 3. Tchebicheff’s mechanism
D. Straight line motion mechanism 4. Double crank
5. Hand pump
a) A-4,B-3,C-5,D-1
b) A-2,B-5,C-1,D-3
c) A-2,B-1,C-5,D-3
d) A-4,B-5,C-2,D-1
Answer: b
Clarification: Pantograph is double lever mechanism. handpump is an inversion of single slider crank chain. Scotch yoke mechanism is an inversion of double slider crank chain.Tchebiceff’s mechanism is an approximate straight line motion mechanism.

3. Match list I with list II
List I List II
A. Scott-Russel 1. Intemittent mechanism motion
B. Geneva 2. Quick return mechanism motion
C. Offset slider crank 3. Simple motion harmonic mechanism
D. Scotch Yoke 4. Straight line mechanism motion

a) A-2,B-3,C-1,D-4
b) A-3,B-2,C-4,D-1
c) A-4,B-1,C-2,D-3
d) A-4,B-3,C-1,D-2
Answer: c
Clarification: Scott-Russel – Straight line mechanism motion
Geneva – Intemittent mechanism motion
Offset slider crank – Quick return mechanism motion
Scotch Yoke – Simple motion harmonic mechanism.

4. When a cylinder is located in a Vee-block, the number of degrees of freedom which are arrested is
a) 2
b) 4
c) 7
d) 8
Answer: b
Clarification: Before placement on Vee-block, cylinder has 6 degrees of freedom. After placement on Vee-block, the cylinder has only 2 degrees of freedom. Hence, the degrees of freedom which are arrested is 6 – 2 = 4.

5. Match list I with list II

Type of joint Motion constrained
A. Revolute 1. Three
B. Cylindrical 2. Five
C. Spherical 3. Four
4. Two
5. Zero
a) A-1,B-3,C-2
b) A-5,B-4,C-3
c) A-2,B-3,C-1
d) A-4,B-5,C-3
Answer: c
Clarification: For revolute pair, degree of freedom = 1 and constrained
DOF = 6 – 1 = 5
For cylindrical pair, dof =2 and constrained dof = 6 – 2 = 4
For spherical pair, dof = 3 and constrained dof = 6 – 3 = 3.

6. The number of binary links, number of binary joints and number of ternary joints in Peaucelliar mechanism is
a) 6,6,0
b) 8,2,4
c) 8,4,2
d) 8,8,0
Answer: b
Clarification: The Peaucelliar mechanism has 8 binary links, 2 binary joints nad 4 ternary joints.

7. The number of degree of freedom of a planer linkage with 8 links and 9 simple revolute joints is
a) 1
b) 2
c) 3
d) 4
Answer: c
Clarification: L = 8 = number of links
P = 9 = number of simple revolute joints

F = 3(L – 1) – 2P
= 3(8 – 1) – 2 x 9
= 21 – 18
= 3.

8. The following list of statements is given:
1) Grashoff’s rule states that for a planar crank-rocker 4-bar mechanism, the sum of the shortest and longest link lengths cannot be less than the sum of the remaining two link lengths.
2) Inversions of a mechanism are created by fixing different links, one at a time.
3) Geneva mechanism is an intermittent motion device.
4) Grubler’s criterion assumes mobility of a planar mechanism to be one.

The number of correct statements in the above list is
a) 1
b) 2
c) 3
d) 4
Answer: c
Clarification: Except statement 1, all other three statements are correct.

9. A mechanism has 8 links, out of which 5 are binary, 2 are ternary and 1 is quaternary. The number of instantaneous centres of rotation will be
a) 28
b) 56
c) 62
d) 66
Answer: d
Clarification: n = 5 + 4 + 3 = 12
Number of instantaneous centres, N = n(n – 1)/2
= 12 x (12 – 1)/2
= 66.

10. In a dynamically equivalent system, a uniformly distributed mass is divided into
a) Three point masses
b) Four point masses
c) Two point masses
d) Infinite point masses
Answer: c
Clarification: Dynamically equivalent system of a rigid body is made of two point masses.

11. A crank and slotted lever mechanism used in a shaper has a centre distance of 300 mm between the centre of oscillation of the slotted lever and the centre of rotation of the crank. The radius of the crank is 120 mm. Find the ratio of the time of cutting to the time of return stroke.
a) 1.62
b) 1.72
c) 1.82
d) 1.92
Answer: b
Clarification: Given : AC = 300 mm ; CB = 120 mm
sin∠CAB = sin (90°−α/ 2)
CB/AC = 120/300 = 0.4

∠CAB = 90°−α/ 2
or α / 2 = 90° – 23.6° = 66.4°
α = 2 × 66.4 = 132.8°

We know that
Time of cutting stroke/ Time of return stroke = 1.72.

12. The magnitude of velocities of the points on a rigid link is directly proportional to the distances from the points to the instantaneous centre.
a) True
b) False
Answer: b
Clarification: The magnitude of velocities of the points on a rigid link is inversely proportional to the distances from the points to the instantaneous centre and is perpendicular to the line joining the point to the instantaneous centre.

13. The velocity of the instantaneous centre relative to any third rigid link will be different.
a) True
b) False
Answer: b
Clarification: The velocity of the instantaneous centre relative to any third rigid link will be same whether the instantaneous centre is regarded as a point on the first rigid link or on the second rigid link.

14. When the pin connects one sliding member and the other turning member, the angular velocity of the sliding member is __________
a) 0
b) 1
c) 2
d) 3
Answer: a
Clarification: When the pin connects one sliding member and the other turning member, the angular velocity of the sliding member is zero. In such cases,
Rubbing velocity at the pin joint = ω.r
where ω = Angular velocity of the turning member, and
r = Radius of the pin.

15. In a slider crank mechanism, the velocity of piston becomes maximum when
a) Crank and connecting rod are in line with each other
b) Crank is perpendicular to the line of stroke of the piston
c) Crank and connecting rod are mutually perpendicular
d) Crank is 1200 with the line of stroke
Answer: b
Clarification: None.

250+ TOP MCQs on Mechanisms with Lower Pairs and Answers

Machine Kinematics Multiple Choice Questions on ” Mechanisms with Lower Pairs”.

1. A pantograph consists of
a) 4 links
b) 6 links
c) 8 links
d) 10 links
Answer: a
Clarification: In a pantograph, all the pairs are turning pairs. It has 4 links.

2. Which of these mechanisms gives an approximately straight line?
a) hart
b) watt
c) peaucellier
d) tchebicheff
Answer: b
Clarification: Watt’s mechanism is a crossed four bar chain mechanism and was used by Watt for his early steam engines to guide the piston rod in a cylinder to have an approximate straight line motion.

3. Which of these mechanism has six links?
a) tchebicheff
b) hart
c) peaucellier
d) watt
Answer: b
Clarification: Hart’s mechanism requires only six links as compared with the eight links required by the Peaucellier mechanism.

4. Which of these mechanisms use two identical mechanisms?
a) hart
b) watt
c) peaucellier
d) none of the mentioned
Answer: d
Clarification: None.

5. The Davis steering gear is not used because
a) it has turning pairs
b) it is costly
c) it has sliding pair
d) it does not fulfil the condition of correct gearing
Answer: b
Clarification: Though the gear is theoretically correct, but due to the presence of more sliding members, the wear will be increased which produces slackness between the sliding surfaces, thus eliminating the original accuracy. Hence Davis steering gear is not in common use.

6. The Davis steering gear fulfils the condition of correct steering at
a) two positions
b) three positions
c) all positions
d) one positions
Answer: c
Clarification: It can be used in all positions.
Ackermann steering gear fulfils the condition of correct steering at only three positions.

7. The Ackermann steering gear fulfils the condition of correct steering at
a) no position
b) one position
c) three positions
d) all positions
Answer: c
Clarification: Ackermann steering gear fulfils the condition of correct steering at only three positions.

8. A Hooke’s joint is used to join two shafts which are
a) aligned
b) intersecting
c) parallel
d) none of the mentioned
Answer: b
Clarification: Hooke’s joint is used to connect two shafts, which are intersecting at a small angle.

9. The maximum velocity of the driven shaft of a Hooke’s joint is
a) ω1 cosα
b) ω1/cosα
c) ω1 sinα
d) ω1/sinα
Answer: b
Clarification: Maximum speed of the driven shaft,
ω1(max) = ωcosα/ 1 – sin2α = ωcosα/cos2α = ω/cosα.

10. The maximum velocity of the driven shaft of a Hooke’s joint is at ϴ equal to
a) 00 and 1800
b) 900 and 2700
c) 900 and 1800
d) 1800 and 2700
Answer: a
Clarification: Maximum velocity is determined at 00 ,1800 and 3600.

250+ TOP MCQs on Friction in Journal Bearing- Friction Circle and Answers

Machine Kinematics Multiple Choice Questions on “Friction in Journal Bearing- Friction Circle”.

1. The minimum force required to slide a body of weight W on a rough horizontal plane is
a) W sinϴ
b) W cosϴ
c) W tanϴ
d) W cosecϴ
Answer: a
Clarification: The minimum force required to slide a body of weight W on a rough horizontal plane is W sinϴ. A body of weight W is required to move up the rough inclined plane whose angle of inclination with the horizontal is α. The effort applied parallel to the plane is given by P = W (sinα + μ cosα).

2. A body will begin to move down an inclined plane, if the angle of inclination of the plane is ____________ the angle of friction.
a) equal to
b) less than
c) greater than
d) none of the mentioned
Answer: c
Clarification: None.

3. A body of weight W is required to move up the rough inclined plane whose angle of inclination with the horizontal is α. The effort applied parallel to the plane is given by
a) P = W tanα
b) P = W tan (α + ɸ)
c) P = W (sinα + μ cosα)
d) P = W (cosα + μ sinα)
Answer: c
Clarification: The minimum force required to slide a body of weight W on a rough horizontal plane is W sinϴ. A body of weight W is required to move up the rough inclined plane whose angle of inclination with the horizontal is α. The effort applied parallel to the plane is given by P = W (sinα + μ cosα).

4. The coefficient of friction is the ratio of the limiting friction to the normal reaction between the two bodies.
a) True
b) False
Answer: a
Clarification: The coefficient of friction is defined as the ratio of the limiting friction(F) to the normal reaction(RN) between the two bodies. Mathematically,
μ = F/RN.

5. In a screw jack, the effort required to lift the load W is given by
a) P = W tan (α – ɸ)
b) P = W tan (α + ɸ)
c) P = W tan (ɸ – α)
d) P = W cos (α + ɸ)
Answer: b
Clarification: The effort required at the circumference of the screw to lift the load W is given by
P = W tan (α + ɸ)
The effort required at the circumference of the screw to lower the load W is given by
P = W tan (ɸ – α).

6. In a screw jack, the effort required to lower the load W is given by
a) P = W tan (α – ɸ)
b) P = W tan (α + ɸ)
c) P = W tan (ɸ – α)
d) P = W cos (α + ɸ)
Answer: c
Clarification: The effort required at the circumference of the screw to lower the load W is given by
P = W tan (ɸ – α)
The effort required at the circumference of the screw to lift the load W is given by
P = W tan (α + ɸ).

7. The frictional torque for square thread at the mean radius r while raising load W is given by
a) T = W.rtan(α – ɸ)
b) T = W.rtan(α + ɸ)
c) T = W.rtanα
d) T = W.rtanɸ
Answer: b
Clarification: None.

8. Efficiency of a screw jack is given by
a) tan(α + ɸ)/tanα
b) tanα/ tan(α + ɸ)
c) tan(α – ɸ)/tanα
d) tanα/tan(α – ɸ)
Answer: b
Clarification: None.

9. The load cup of a screw jack is made separate from the head of the spindle to
a) enhance the load carrying capacity of the jack
b) reduce the effort needed for lifting the working load
c) reduce the value of frictional torque required to be countered for lifting the load
d) prevent the rotation of load being lifted
Answer: d
Clarification: In screw jack, the load to be raised or lowered, is placed on the head of the square threaded rod which is rotated by the application of an effort at the end of the lever for lifting or lowering the load.

10. The efficiency of the a screw jack is maximum, when
a) α = 450 + ɸ/2
b) α = 450 – ɸ/2
c) α = 900 + ɸ
d) α = 900 – ɸ
Answer: b
Clarification: None.

250+ TOP MCQs on The Differential & Torques in Epicyclic Gear Trains and Answers

Machine Kinematics Questions & Answers for Exams on “The Differential & Torques in Epicyclic Gear Trains”.

1. To split the engine torque in two ways, which of the following device is used?
a) Clutch
b) Brake
c) Final drive
d) Differential
Answer: d
Clarification: The differential is a device that splits the engine torque two ways, allowing each output to spin at a different speed and hence considered as an immensely important device in the modern vehicles.

2. Two wheelers are also equipped with a differential.
a) True
b) False
Answer: b
Clarification: The differential is found on all modern cars and trucks, and also in many all-wheel-drive vehicles. Two wheelers do not have a differential.

3. Which of the following device allows the wheels of a car to rotate at two different speeds?
a) Clutch
b) Brake
c) Final drive
d) Differential
Answer: d
Clarification: The differential is a device that splits the engine torque two ways, allowing each output to spin at a different speed. The differential plays an integral role in how a car makes turns.

4. Which of the following is true regarding a differential?
a) The outer wheel rotates at a higher speed than the inner wheel
b) The outer wheel rotates at a lower speed than the inner wheel
c) Both the wheels rotate at the same speed
d) Front wheels rotate at a lower speed than rear wheel
Answer: a
Clarification: Since the outer wheels of a car has to travel a greater distance, the outer wheel must rotate at a higher speed in order to prevent slipping.

5. The ratio of speeds between gears is dependent upon the _________
a) Ratio of teeth between the two adjoining gears
b) Ratio of teeth between the two alternate gears
c) Ratio of acceleration
d) Ratio of velocity
Answer: a
Clarification: The ratio of speeds between gears is dependent upon the ratio of teeth between the two adjoining gears such that w1 x N1 = w2 x N2 where w1 is the teeth of gear one and N1 is the speed.

6. On a straight road motion, what is the purpose served by differential?
a) Equal torque to all the wheels
b) More torque to front wheels
c) More torque to rear wheels
d) More torque to opposite wheels
Answer: a
Clarification: When the car is traveling straight, both wheels travel at the same speed. This is done by providing equal torque to all the wheels.

7. Input torque acts on which of the following member?
a) Driven member
b) Driving member
c) Fixed member
d) Reciprocating member
Answer: b
Clarification: If the rotating parts of an epicyclic gear trains does not undergo any acceleration then it is kept in equilibrium by an externally applied torques. The input torque is one of them and acts on the driving member.

8. Resisting torque acts on which of the following member?
a) Driven member
b) Driving member
c) Fixed member
d) Reciprocating member
Answer: a
Clarification: If the rotating parts of an epicyclic gear trains does not undergo any acceleration then it is kept in equilibrium by an externally applied torques. The input torque is one of them and acts on the driven member.

9. Braking torque acts on which of the following member?
a) Driven member
b) Driving member
c) Fixed member
d) Reciprocating member
Answer: c
Clarification: If the rotating parts of an epicyclic gear trains does not undergo any acceleration then it is kept in equilibrium by an externally applied torques. The input torque is one of them and acts on the fixed member.

10. If the input power is increased to two times, what will be the effect of it on the fixed member power?
a) Has a 0 value
b) Increases by two times
c) Increases by 4 times
d) Decreases by two times
Answer: a
Clarification: Since the fixed member does not rotate, the power transmitted by it is 0. As a result of this it remains unaffected by change in input power.

11. If the ratio of angular velocities of the driven and driving torque is one, find the Braking torque
a) 0
b) 2
c) 4
d) 8
Answer: a
Clarification: We know the relation
T2 = -T1ω1/ω2
since the velocity ratio is 1
we have T2 + T1 = 0
now
T3 = T2 + T1
Therefore, T3 = 0.

12. The angular speed of the driven member is twice the driving member, if the input torque is 100 N-m,
Find the load torque magnitude in N-m.
a) 50
b) 100
c) 200
d) 25
Answer: a
Clarification: We know the relation
T2 = -T1ω1/ω2
since the velocity ratio is 1⁄2
we have T2 = 50 N-m.

13. Fixing torque’s value is independent of the load torque.
a) True
b) False
Answer: b
Clarification: Fixing torque or the braking torque or the Holding torque generally represented by T3 has a value
T3 = -(T2 + T1)
therefore its value is dependent on the load torque.

14. Load torque is directly proportional to the input angular velocity.
a) True
b) False
Answer: a
Clarification: We know that Load torque is given by
T2 = -T1ω1/ω2 where ω1 is the input angular velocity. Hence the given statement is correct.

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250+ TOP MCQs on Path of Contact and Answers

Machine Kinematics Puzzles on “Path of Contact”.

1. Which of the following is a commonly used pressure angle in gears?
a) 20
b) 10
c) 12
d) 17
Answer: a
Clarification: The pressure angle is the angle between the tangent to the pitch circles and the line drawn normal (perpendicular) to the surface of the gear teeth. It has a set of standard values which is accepted globally, 20° is one of them.

2. Addendum circle of the gear wheel has the shortest radius.
a) True
b) False
Answer: b
Clarification: Addendum circle of the gear wheel has the largest radius, the base circle has the smallest radius. Addendum of the gear plays a vital role in determining whether interference will take place or not.

3. Which of the following is true for Length of arc of contact?
a) Sum of Arc of recess and Arc of approach
b) Difference of arc of approach and arc of recess
c) Twice the arc of approach
d) Twice the arc of recess
Answer: a
Clarification: The arc of contact is given by the sum of Length of arc of approach and length of arc of recess. Numerically it is the ratio of length of path of contact and the cosine of the pressure angle.

4. Which of the following is true for Length of path of contact?
a) Sum of path of recess and path of approach
b) Difference of path of approach and path of recess
c) Twice the arc of approach
d) Twice the path of recess
Answer: a
Clarification: The path of contact is given by the sum of Length of path of approach and length of path of recess. Numerically it is dependent on pitch radius, addendum radius and the sine of pressure angle.

5. From the following data, find the addendum in mm:
Teeth on each wheel: 40
Pressure angle: 20°
Module: 6mm
Arc of contact/ pitch: 1.75
a) 6.12
b) 6.51
c) 6.61
d) 6.81
Answer: a
Clarification: Pc = πm = 18.85mm
Arc of contact = 1.75xp = 33mm
Length of path of contact = cosΦx Arc of contact
From another relation of length of path of contact we get
Ra = 126.12 mm
R = 120mm
Therefore addendum = 6.12mm.

6. From the following data:
Teeth on pinion: 30
Teeth on gear: 80
Pressure angle: 20°
Module: 12mm
Addendum: 10mm
Find the length of path of contact in mm.
a) 52.3
b) 55.4
c) 53.2
d) 54.5
Answer: a
Clarification: R = mT/2 = 480mm
r = mt/2 = 180mm
Addendum radius of pinion = 190mm
Addendum radius of gear = 490mm
Using the relation for length of path of approach
We get path of approach = 27.3mm
Path of recess = 25mm
adding both we get total length of path of contact
= 52.3mm.

7. From the following data:
Teeth on pinion: 30
Teeth on gear: 80
Pressure angle: 20°
Module: 12mm
Addendum: 10mm
Find the length of arc of contact in mm.
a) 52.333
b) 55.66
c) 53.22
d) 54.55
Answer: b
Clarification: R = mT/2 = 480mm
r = mt/2 = 180mm
Addendum radius of pinion = 190mm
Addendum radius of gear = 490mm
Using the relation for length of path of approach
We get path of approach = 27.3mm
Path of recess = 25mm
adding both we get total length of path of contact
= 52.3mm
Length of arc of contact = length of path of contact / cosΦ
= 55.66mm.

8. Maximum sliding velocity is the sum of angular velocities and its product with the length of path of contact.
a) True
b) False
Answer: b
Clarification: Maximum sliding velocity is the sum of angular velocities and its product with the length of path of appraoch.
Vs = (ω2 + ω1)x(length of path of approach).

9. From the following data:
Teeth on pinion: 30
Teeth on gear: 80
Pressure angle: 20°
Module: 12mm
Addendum: 10mm
Find the contact ratio.
a) 1.5
b) 1.75
c) 2
d) 1,33
Answer: b
Clarification: R = mT/2 = 480mm
r = mt/2 = 180mm
Addendum radius of pinion = 190mm
Addendum radius of gear = 490mm
Using the relation for length of path of approach
We get path of approach = 27.3mm
Path of recess = 25mm
adding both we get total length of path of contact
= 52.3mm
Length of arc of contact = length of path of contact / cosΦ
Contact ratio = Length of arc of contact/Pc
=1.75.

10. Find maximum sliding velocity in cm/s from the given data
addendum = 1 module = 5mm
Pitch line speed = 1.2m/s
Pressure angle of involute profile: 20 degrees
Tp = 20
Gear ratio = 2
a) 45.5
b) 46.8
c) 45.1
d) 47.2
Answer: a
Clarification: We know that
V = ω1r = ω2R
120/(mt/2) = ω1
ω1 = 24 rad/s
similarly
ω2 = 12 rad/s
Now maximum sliding velocity = (ω2 + ω1)x(length of path of approach)
= 455.4 mm/s
= 45.5 cm/s.

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250+ TOP MCQs on Relation Between Linear Motion and Angular Motion and Answers

Machine Kinematics Questions and Answers for Freshers on “Relation Between Linear Motion and Angular Motion”.

1. Which of the following disciplines provides study of inertia forces arising from the combined effect of the mass and motion of the parts?
a) theory of machines
b) applied mechanics
C) kinematics
d) kinetics
Answer: d
Clarification: The study of inertia forces arising from the combined effect of the mass and motion of the parts is called kinetics.
The study of relative motion between the parts of a machine is called kinematics.
The study of the relative motion between the parts of a machine and the forces acting on the parts is called theory of machines.

2. Which of the following disciplines provides study of relative motion between the parts of a machine?
a) theory of machines
b) applied mechanics
C) kinematics
d) kinetics
Answer: c
Clarification: The study of inertia forces arising from the combined effect of the mass and motion of the parts is called kinetics.
The study of relative motion between the parts of a machine is called kinematics.
The study of the relative motion between the parts of a machine and the forces acting on the parts is called theory of machines.

3. Which of the following disciplines provides study of the relative motion between the parts of a machine and the forces acting on the parts?
a) theory of machines
b) applied mechanics
C) kinematics
d) kinetics
Answer: a
Clarification: The study of inertia forces arising from the combined effect of the mass and motion of the parts is called kinetics.
The study of relative motion between the parts of a machine is called kinematics.
The study of the relative motion between the parts of a machine and the forces acting on the partsis called theory of machines.

4. The type of pair formed by two elements which are so connected that one is constrained to turn or revolve about a fixed axis of another element is known as
a) turning pair
b) rolling pair
c) sliding pair
d) spherical pair
Answer: a
Clarification: When two elements of a pair are connected in such a way that one can only turn or revolve about a fixed axis of another link, the pair is known as turning pair.

5. Which of the following is a lower pair?
a) ball and socket
b) piston and cylinder
c) cam and follower
d) both a and b
Answer: d
Clarification: In both ball and socket and piston cylinder there is surface contact between the two elements. Hence, they form a lower pair.

6. If two moving elements have surface contact in motion, such pair is known as
a) sliding pair
b) rolling pair
c) surface pair
d) lower pair
Answer: d
Clarification: when two elements of a pair have a surface contact when relative motion takes place and the surface of one element slides over the surface of the other, the pair formed is known as lower pair.

7. The example of lower pair is
a) shaft revolving in a bearing
b) straight line motion mechanisms
c) automobile steering gear
d) all of the mentioned
Answer: d
Clarification: In all the mentioned elements there is surface contact between the two elements. Hence, they form a lower pair.

8. Pulley in a belt drive acts as
a) cylindrical pair
b) turning pair
c) rolling pair
d) sliding pair
Answer: c
Clarification: When the two elements of a pair are connected in such a way that one rolls over another fixed link, the pair is known as rolling pair. In belt and pulley, the belt rolls over the pulley.

9. The example of rolling pair is
a) bolt and nut
b) lead screw of a lathe
c) ball and socket joint
d) ball bearing and roller bearing
Answer: d
Clarification: In ball bearing and roller bearing one element rolls over the other element. Hence, they are examples of rolling pair.

10. Any point on a link connecting double slider crank chain will trace a
a) straight line
b) circle
c) ellipse
d) parabola
Answer: c
Clarification: One of the inversions of a double slider crank chain is elliptical trammels. So, from the above given options ellipse is best suited.

11. The purpose of a link is to
a) transmit motion
b) guide other links
c) act as a support
d) all of the mentioned
Answer: d
Clarification: None

12. A universal joint is an example of
a) higher pair
b) lower pair
c) rolling pair
d) sliding pair
Answer: b
Clarification: In universal joint, there is surface contact between the two elements. Hence, they form a lower pair.

13. Rectilinear motion of piston is converted into rotary by
a) cross head
b) slider crank
c) connecting rod
d) gudgeon pin
Answer: b
Clarification: In single slider crank chain rotary motion is converted into reciprocating motion.