2ND 3

Question 1

The revolving runner of a hydraulic turbine is said to have:

a) rectilinear plane motion
b) curvilinear plane motion
c) rotating plane motion
d) a combination of all three motions

Answer 1

c) rotating plane motion

Question 2

The balls of the fly-ball governor, when the speed of rotation is increasing or decreasing, is said to have:

a) helical motion
b) spherical motion
c) intermittent motion
d) plane motions

Answer 2

b) spherical motion

Question 3

Critical speed is defined as:

a) any speed above designed operating speed
b) any speed below designed operating speed
c) that speed for which protective devices are set to trip
d) a speed that creates a centrifugal force greater than the elastic force of the shaft

Answer 3

d) a speed that creates a centrifugal force greater than the elastic force of the shaft

Question 4

All of the below statements concerning critical speed are true except:

a) critical speed is determined by the weight and dimensions of a shaft
b) machines designed to operate below the critical speed are said to have rigid shafts
c) most all hydraulic turbine units have rigid shafts
d) each shaft will have only one critical speed

Answer 4

d) each shaft will have only one critical speed

Question 5

A mechanism that produces the snapping action when circuit breakers are opened or closed uses the principle of the:

a) toggle
b) bell crank
c) pitman
d) ratchet

Answer 5

a) toggle

Question 6

Which one of the below statements concerning belts and pulleys is not true?

a) “V” belts should be fitted to ride more towards the top and less towards the bottom of the pulley
b) protective guards should generally be installed around moving belts
c) the purpose of the idler is to reverse the direction of rotation of a belt drive
d) flat belt pulleys are “crowned” to help keep flat belts running in the center of the pulley

Answer 6

c) the purpose of the idler is to reverse the direction of rotation of a belt drive

Question 7

Select one of the below statements concerning gears that is false:

a) spur gears transmit motion between parallel shafts
b) helical gear teeth create an end thrust
c) herringbone gears cause end thrust on the shafts
d) bevel gears transmit rotary motion around a corner

Answer 7

c) herringbone gears cause end thrust on the shafts

Question 8

Most flexible couplings:

a) are designed to compensate for large amounts of shaft misalignment
b) are designed to fail under high torque loads
c) require some form of lubrication to reduce friction
d) use rubber bushings to absorb shaft misalignment

Answer 8

c) require some form of lubrication to reduce friction

Question 9

Hydraulic couplings are generally used with:

a) variable speed units
b) constant speed units
c) high speed units
d) slow speed units

Answer 9

a) variable speed units

Question 10

Magnetic drives can be used as a:

a) clutch
b) slip coupling
c) reversible drive
d) all three

Answer 10

d) all three