When a belt drive is transmitting maximum power,
Effective tension is equal to centrifugal tension
Effective tension is half of centrifugal tension
Driving tension on slack side is equal to centrifugal tension
Driving tension on tight side is twice the centrifugal tension
Correct Answer :
D. Driving tension on tight side is twice the centrifugal tension
Related Questions
When compared to the rod of the same diameter and material, a wire rope
Is less flexible
Has a much smaller load carrying capacity
Does not provide much warning before failure
Provides much greater time for remedial action before failure
The material commonly used for crane hooks is
Cast iron
Wrought iron
Mild steel
Aluminium
For a shaft diameter of 200 mm, the number of bolts in a marine flange coupling should be
8
6
4
10
For hardening alloy steels and high speed steels, they are heated to
1100 to 1300°C
1300 to 1500°C
500 to 600°C
700 to 900°C
A connecting rod subjected to an axial load may buckle with
X-axis as neutral axis
Y-axis as neutral axis
X-axis or Y-axis as neutral axis
Z-axis
Stress concentration in cyclic loading is more serious in
Ductile materials
Brittle materials
Equally serious in both cases
Depends on other factors
In a multiple V-belt drive, if one of the belts break, then
Only the broken belt is replaced
The entire set of belts is replaced
The broken belt and the belt on either side of it, is replaced
The broken belt need not to be replaced
The objective of crowning of the flat pulleys of belt drive is to
Prevent the belt from running off the pulley
Increase the power transmission capacity
Increase the belt velocity
Prevent the belt joint from damaging the belt surface
Fibrous fracture occurs in
Ductile material
Brittle material
Elastic material
Hard material
The shock resistance of steel is increased by adding
Nickel
Chromium
Nickel and chromium
Cobalt and molybdenum
The rolling contact bearings as compared to sliding contact bearings have
Low starting and low running friction except at very high speeds
Accuracy of shaft alignment
Small overall dimensions
All of the above
A feather key is generally
Loose in shaft and tight in hub
Tight in shaft and loose in hub
Tight in both shaft and hub
Loose in both shaft and hub
The stiffness of a closely coiled helical spring subjected to an axial load W is equal to (where G = Modulus of rigidity, and n = Number of active coils)
Gd⁴/ 8D3n
Gd3/ 8D3n
Gd⁴/ 4D3n
Gd⁴/ 8D²n
The ratio of driving tensions in V-belt drives is __________ flat belt drives.
Equal to
sinα times more than
sinα times less than
cosecα times more than
When the screw in a mechanical screw jack rotates, the load kept on the top of it moves
Axially upwards
Axially downwards
Axially upwards or downwards
None of these
When the length of the journal is equal to the diameter of the journal, then the bearing is said to be a
Short bearing
Long bearing
Medium bearing
Square bearing
If threads on a bolt are left hand, threads on nut will be
Right hand with same pitch
Left hand with same pitch
Could be left or right hand
Right hand with fine pitch
In designing a connecting rod, it is considered like __________ for buckling about X-axis.
Both ends hinged
Both ends fixed
One end fixed and the other end hinged
One end fixed and the other end free
Oil in journal bearing should be applied at the point where load is
Nil or lightest
Maximum
Average
Any one of the above
The largest diameter of an external or internal screw thread is known as
Minor diameter
Major diameter
Pitch diameter
None of these
A single strap butt joint is always in __________ shear.
Single
Double
Triple share
None of these
The connecting rod bolts are tightened up so that tightening stress
Is just sufficient to hold parts together
Approaches yield point
Is 50% of yield point
Is about yield point divided by safety factor
Which of the following is not correct procedure to increase the fatigue limit?
Cold working
Shot peening
Surface decarburisation
Under stressing
A backing ring is used inside the pipe joint when making a
Butt weld
Fillet weld
Sleeve weld
Socket weld
If T is the actual number of teeth on a helical gear and φ is the helix angle for the teeth, then formative number of teeth is written as
T sec3φ
T sec²φ
T/sec3φ
T cosecφ
The expression 0.175 - 0.841/T is the Lewis form factor for
14 ½° composite and full depth involute system
20° full depth involute system
20° stub system
None of the above
The crest diameter of a screw thread is same as
Major diameter
Minor diameter
Pitch diameter
Core diameter
A hollow saddle key is
A taper key which fits half in the key way of hub and half in the key way of shaft
A taper key which fits in a key way of the hub and is flat on the shaft
A taper key which fits in a key way of the hub and the bottom of the key is shaped to fit the curved surface of the shaft
Provided in pairs at right angles and each key is to withstand torsion in one direction only
Which of the following statement is wrong?
A key is used as a temporary fastening
A key is subjected to tensile stresses
A key is always inserted parallel to the axis of the shaft
A key prevents relative motion between the shaft and boss of the pulley
A transmission shaft includes
Over head shaft
Counter shaft
Line shaft
All of these