# Multiple choice question for engineering

## Set 1

1. The included angle for the V-belt is usually

a) 20° – 30°

b) 30° – 40°

c) 40° – 60°

d) 60° – 80°

### View Answer

2. The V-belts are particularly suitable for _____________ drives.

a) short

b) long

c) medium

d) none of the mentioned

### View Answer

3. The groove angle of the pulley for V-belt drive is usually

a) 20° – 25°

b) 25° – 32°

c) 32° – 38°

d) 38° – 45°

### View Answer

4. A V-belt designated by A-914-50 denotes

a) a standard belt

b) an oversize belt

c) an undersize belt

d) none of the mentioned

### View Answer

5. The wire ropes make contact at

a) bottom of groove of the pulley

b) sides of groove of the pulley

c) sides and bottom of groove of the pulley

d) any where in the groove of the pulley

### View Answer

6. Which of the following statements are correct regarding power transmission through V-belts?

(i) V-belts are used at the high-speed end.

(ii) V-belts are used at the low-speed end.

(iii) V-belts are of standard lengths.

(iv) V-angles of pulleys and belts are standardized.

Select the correct answer using the code given below.

a) 1 and 3 only

b) 2 and 4 only

c) 2, 3 and 4

d) 1, 3 and 4

### View Answer

7. The creep in a belt drive is due to the

a) material of the pulleys

b) material of the belt

c) unequal size of the pulleys

d) unequal tension in tight and slack sides of the belt

### View Answer

8. In order to have a good grip on the pulley, the V-belt should touch the bottom of the groove in the pulley.

a) True

b) False

### View Answer

## Set 2

1. The lengths of the links of a 4- bar linkage with revolute pairs only are p,q,r and s units. Given that p < q < r < s and s+p < q+r which of these links should be the fixed one, for obtaining a ‘double crank’ mechanism?

a) ink of length p

b) link of length q

c) link of length r

d) link of length s

### View Answer

2. For a four-bar linkage in toggle position, the value of mechanical advantage is

a) 0.0

b) 0.5

c) 1.0

d) ∞

### View Answer

3. In a slider-crank mechanism, the crank is rotating with an angular velocity of 20 rad/s in counterclockwise direction. At the instant when the crank is perpendicular to the direction of the piston movement, velocity of the piston is 2 m/s. Radius of the crank is

a) 100 cm

b) 10 cm

c) 1 cm

d) 0.1 cm

### View Answer

_{p}= ωr(sinϴ + sin2ϴ/2n) In this case ϴ = 90

^{0}V

_{p}= ωr r = V

_{p}/ω = 2/20 = 0.1 m or 10 cm.

4. In a single link robotic arm the end-effector slides upward along the link with a velocity of 0.5 m/s while the link rotates about revolute joint with an angular speed of 1 rad/sec. When the end-effector is at a distance of 1 m from the joint, the acceleration experienced by the end-effector will be

a) 1 m/s^{2}

b) 1.41 m/s^{2}

c) 1.71 m/^{2}

d) 2 m/^{2}

### View Answer

^{2}.

5. For the same crank length and uniform angular velocity of the crank in an offset slider crank mechanism, if the connecting rod length is increased by 1.5 times, the velocity of piston will

a) remain unchanged

b) increase 1.5 times

c) decrease by 1.5 times

d) increase by 1.5√2 times

### View Answer

_{1}= ωr(sinϴ + sin2ϴ/2n) V

_{2}= ωr(sinϴ + sin2ϴ/3n) from these two equation, V

_{2}< V

_{1}V

_{2}will decrease but correct quantification can not be done with available data. Among the available options, best answer is (c).

6. It is planned to construct a four-bar mechanism ABCD with length AB= 60mm, BC = 100mm, CD = 70 mm and fixed link AD = 200 mm. If at least one link is required to have a complete rotation, this mechanism is

a) of crank-rocker type

b) of double-crank type

c) of double rocker type

d) impossible to construct

### View Answer

7. The number of links in a planer mechanism with revolute joints having 10 instantaneous centres is

a) 3

b) 4

c) 5

d) 6

### View Answer

8. A weston differential pulley block consists of a lower block and upper block. The upper block has two cogged grooves, one of which has a radius of 150 mm and the other a radius of 125 mm. If the efficiency of the machine is 50% calculate the effort required to raise a load of 1.5 kN.

a) 250 N

b) 300 N

c) 350 N

d) 400 N

### View Answer

Again, M.A. = W/P 6 = 1.5 x 1000/ P P = 250 N.

9. Following are the specifications of a single purchase crab:

Diameter of load drum, d = 200 mm

Length of lever, l = 1.2 m

No. of teeth on pinion, T_{1} = 10

No. of teeth on spur wheel, T_{2} = 100

Find the velocity ratio of this machine.

a) 100

b) 110

c) 120

d) 130

### View Answer

_{2}/T

_{1}= 2 x 120/20 x 100/10 = 120.

10. On a machine efforts of 100 N and 160 N are required to lift the loads of 3000 N and 9000 N respectively. Find the law of the machine.

a) P = 1/100W + 60

b) P = 1/100W + 70

c) P = 1/100W + 80

d) P = 1/100W + 90

### View Answer

Subtracting (i) and (ii), we get 60 = 6000 m or, m = 1/100 Putting this value in equation (i), we get 100 = 3000 x 1/100 + C C = 70

Hence, the machine follows the laws P = 1/100W +70.

11. Following are the specifications of a single purchase crab:

Diameter of load drum, d = 200 mm

Length of lever, l = 1.2 m

No. of teeth on pinion, T_{1} = 10

No. of teeth on spur wheel, T_{2} = 100

On this machine efforts of 100 N and 160 N are required to lift the loads of 3000 N and 9000 N respectively. Find the efficiency at 3000N.

a) 10 %

b) 15 %

c) 20 %

d) 25 %

### View Answer

_{2}/T

_{1}= 2 x 120/20 x 100/10 = 120 M.A. = W/P = 3000/100 = 30

Efficiency = M.A./V.R. = 30/120 = 0.25 = 25%.

12. Following are the specifications of a single purchase crab:

Diameter of load drum, d = 200 mm

Length of lever, l = 1.2 m

No. of teeth on pinion, T_{1} = 10

No. of teeth on spur wheel, T_{2} = 100

On this machine efforts of 100 N and 160 N are required to lift the loads of 3000 N and 9000 N respectively. Find the efficiency at 9000N.

a) 30 %

b) 40 %

c) 46.8 %

d) 56.8 %

### View Answer

_{2}/T

_{1}= 2 x 120/20 x 100/10 = 120 M.A. = W/P = 9000/160 = 900/16

Efficiency = M.A./V.R. = 900/16 x 120 = 0.468 = 46.8%.

## Set 3

1. The coriolis component of acceleration exists whenever a point moves along a path that has

a) linear displacement

b) rotational motion

c) gravitational acceleration

d) tangential acceleration

### View Answer

2. In a pantograph, all the pairs are

a) turning pairs

b) sliding pairs

c) spherical pairs

d) self-closed pairs

### View Answer

3. Which of the following mechanism is made up of turning pairs?

a) Scott Russel’s mechanism

b) Peaucellier’s mechanism

c) Hart’s mechanism

d) All of the mentioned

### View Answer

4. Scott Russel’s mechanism is made up of sliding pair.

a) True

b) False

### View Answer

5. An exact straight line motion mechanism is a

a) Scott-Russell’s mechanism

b) Hart’s mechanism

c) Peaucellier’s mechanism

d) All of the mentioned

### View Answer

6. Which of the following mechanism is an approximate straight line motion mechanism?

a) Watt’s mechanism

b) Grasshopper mechanism

c) Robert’s mechanism

d) All of the mentioned

### View Answer

7. The fundamental equation for correct steering is

a) sinɸ + sinα = b/c

b) cosɸ – sinα = c/b

c) cotɸ – cotα = c/b

d) tanɸ + cotα = b/c

### View Answer

where ɸ and α = Angle through which the axix of the outer wheel and inner wheel turns respectively c = Distance between the pivots of the front axles b = Wheel base.

8. The condition for correct steering of a Davis steering is

a) sinα = b/c

b) cosα = c/b

c) tanα = c/2b

d) cotα = c/2b

### View Answer

9. The driving and driven shafts connected by a Hooke’s joint will have equal speeds, if

a) cosϴ = sinα

b) sinϴ = √tanα

c) tanϴ = √cosα

d) cotϴ = cosα

### View Answer

10. The Ackerman steering gear mechanism is preferred to the Davis steering gear mechanism because

a) whole of the mechanism in the Ackerman steering gear is on the back of the front wheels

b) the Ackerman steering gear consists of turning pairs

c) the Ackerman steering gear is most economical

d) both a and b

### View Answer

## Set 4

1. The instantaneous centre is a point which is always fixed.

a) True

b) False

### View Answer

2. The angular velocity of a rotating body is expressed in terms of

a) revolution per minute

b) radians per second

c) any one of the mentioned

d) none of the mentioned

### View Answer

3. The linear velocity of a rotating body is given by the relation

a) v = rω

b) v = r/ω

c) v = ω/r

d) v = ω^{2}/r

### View Answer

4. The linear acceleration of a rotating body is given by the relation

a) a = rα

b) a = r/α

c) a = α/r

d) a = α^{2}/r

### View Answer

5. The relation between linear velocity and angular velocity of a cycle

a) exists under all conditions

b) does not exist under all conditions

c) exists only when it does not slip

d) exists only when it moves on horizontal plane

### View Answer

6. The velocity of piston in a reciprocating pump mechanism depends upon

a) angular velocity of the crank

b) radius of the crank

c) length of the connecting rod

d) all of the mentioned

### View Answer

7. The linear velocity of a point B on a link rotating at an angular velocity ω relative to another point A on the same link is

a) ω^{2}AB

b) ωAB

c) ω(AB)^{2}

d) ω/AB

### View Answer

8. The linear velocity of a point relative to another point on the same link is ……….. to the line joining the points.

a) perpendicular

b) parallel

c) at 45^{0}

d) none of the mentioned

### View Answer

9. According to Kennedy’s theorem the instantaneous centres of three bodies having relative motion lie on a

a) curved path

b) straight line

c) point

d) none of the mentioned

### View Answer

10. The instantaneous centers of a slider moving in a linear guide lies at

a) pin joints

b) their point of contact

c) infinity

d) none of the mentioned

### View Answer

## Set 5

1. When bevel gears having equal teeth and equal pitch angles connect two shafts whose axes intersect at right angle, then they are known as

a) angular bevel gears

b) crown bevel gears

c) internal bevel gears

d) mitre gears

### View Answer

2. The face angle of a bevel gear is equal to

a) pitch angle – addendum angle

b) pitch angle + addendum angle

c) pitch angle – dedendum angle

d) pitch angle + dedendum angle

### View Answer

3. The root angle of a bevel gear is equal to

a) pitch angle – addendum angle

b) pitch angle + addendum angle

c) pitch angle – dedendum angle

d) pitch angle + dedendum angle

### View Answer

_{R}’. It is equal to the pitch angle minus dedendum angle.

4. If b denotes the face width and L denotes the cone distance, then the bevel factor is written as

a) b / L

b) b / 2L

c) 1 – 2 b.L

d) 1 – b / L

### View Answer

5. For a bevel gear having the pitch angle θ, the ratio of formative number of teeth (T_{E}) to actual number of teeth (T) is

a) 1/sin θ

b) 1/cos θ

c) 1/tan θ

d) sin θ cos θ

### View Answer

_{E})/T = 1/cos θ.

6. The worm gears are widely used for transmitting power at ______________ velocity ratios between non-intersecting shafts.

a) high

b) low

c) medium

d) none of the mentioned

### View Answer

7. In worm gears, the angle between the tangent to the thread helix on the pitch cylinder and the plane normal to the axis of worm is called

a) pressure angle

b) lead angle

c) helix angle

d) friction angle

### View Answer

8. The normal lead, in a worm having multiple start threads, is given by

a) l_{N} = l / cos λ

b) l_{N} = l . cos λ

c) l_{N} = l

d) l_{N} = l tan

### View Answer

_{N}) is used, such that l

_{N}= l . cos λ where l

_{N}= Normal lead, l = Lead, and λ = Lead angle.

9. The number of starts on the worm for a velocity ratio of 40 should be

a) single

b) double

c) triple

d) quadruple

### View Answer

10. The axial thrust on the worm (W_{A}) is given by

a) W_{A} = W_{T} . tan φ

b) W_{A} = W_{T} / tan φ

c) W_{A} = W_{T} . tan λ

d) W_{A} = W_{T} / tan λ

### View Answer

_{A}= W

_{T}/ tan λ = Tangential force on the worm gear where W

_{T}= Tangential force acting on the worm, φ = Pressure angle, and λ = Lead angle.