# Practice Test: Question Set - 05

**1. Lower pairs are those which have**

- (A) Point or line contact between
the two elements when in motion

- (B) Surface
contact between the two elements when in motion

- (C) Elements
of pairs not held together mechanically

- (D) Two
elements that permit relative motion

**2. A system in dynamic balance implies that**

- (A) The
system is critically damped

- (B) There
is no critical speed in the system

- (C) The
system is also statically balanced

- (D) There
will absolutely no wear of bearings

**3. The Coriolis component of acceleration leads the sliding velocity by**

- (A) 45°

- (B) 90°

- (C) 135°

- (D) 180°

**4. The power of a Porter governor is equal to**

- (A)

*[c²/(1*+

*2c)] (m*+

*M) g.h*

- (B)

*[2c²/(1*+

*2c)] (m*+

*M) g.h*

- (C)

*[3c²/(1*+

*2c)] (m*+

*M) g.h*

- (D)

*[4c²/(1*+

*2c)] (m*+

*M) g.h*

**5. In the two rotor system as shown in the below figure (**

*I₁*<*I₂*), a node of vibration is situated- (A) Between

*I₁*, and

*I₂*but nearer

*I₁*

- (B) Between

*I₁*, and

*I₂*but nearer to

*I₂*

- (C) Exactly
in the middle of the shaft

- (D) Nearer to

*I₁*but outside

**6. Whitworth quick return mechanism is obtained by inversion of**

- (A) Slider
crank mechanism

- (B) Kinematic chain

- (C) Five
link mechanism

- (D) Roller
cam mechanism

**7. In a four-bar chain it is required to give an oscillatory motion to the follower for a continuous rotation of the crank. For the lengths of 50 mm of crank and 70 mm of the follower, determine theoretical maximum length of coupler. The minimum length of the coupler will be**

- (A) 45 mm

- (B) Slightly less than 45 mm

- (C) Slightly
more than 45 mm

- (D) 95 mm

**8. The Grubler's criterion for determining the degrees of freedom (**

*n*) of a mechanism having plane motion is (where*l*= Number of links, and*j*= Number of binary joints)- (A)

*n*

*= (l -1) - j*

- (B)

*n*

*=*2

*(l - 1) -*2

*j*

- (C)

*n*

*=*3

*(l - 1) -*2

*j*

- (D)

*n*

*=*4

*(l - 1) -*3

*j*

**9. For dynamic balancing of a shaft**

- (A) The
net dynamic force acting on the shaft is equal to zero

- (B) The
net couple due to the dynamic forces acting on the shaft is equal to zero

- (C) Both (A) and
(B)

- (D) None
of the above

**10. The periodic time of a compound pendulum is __________ when the distance between the point of suspension and the center of gravity is equal to the radius of gyration of the body about its center of gravity.**

- (A) Zero

- (B) Minimum

- (C) Maximum

- (D) None of
these

**11. Which is the false statement about the properties of instantaneous center?**

- (A) At the instantaneous center
of rotation, one rigid link rotates instantaneously relative to another for the
configuration of mechanism considered

- (B) The
two rigid links have no linear velocities relative to each other at the
instantaneous center

- (C) The
two rigid links which have no linear velocity relative to each other at this
center have the same linear velocity to the third rigid link

- (D) The
double center can be denoted either by O

_{2}\ or O

_{12}, but proper selection should be made

**12. Which of the following statement is correct?**

- (A) The primary
unbalanced force is less than the secondary unbalanced force

- (B) The
primary unbalanced force is maximum twice in one revolution of the crank

- (C) The
unbalanced force due to reciprocating masses varies in magnitude and direction
both

- (D) The
magnitude of swaying couple in locomotives is inversely proportional to the
distance between the two cylinder center lines

**13. The distance by which the __________ of the D-slide valve overlaps the steam port is called exhaust lap.**

- (A) Inner edge

- (B) Outer edge

- (C) Corners

- (D) None of
these

**14. In a Hartnell governor, the stiffness of the spring is given by (where**

*S*1 and*S*2 = Spring forces exerted on the sleeve at max. and min. radii of rotation, and*h*= Compression of the spring)- (A)

*(S₁*+

*S₂) / h*

- (B)

*(S₁*-

*S₂) / h*

- (C)

*(S₁*+

*S₂) /*2

*h*

- (D)

*(S₁*-

*S₂) /*2

*h*

**15. The number of centers in a crank driven slider crank mechanism is**

- (A) 0

- (B) 2

- (C) 4

- (D) 6

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