The minimum number of teeth on the pinion which will mesh with any gear without interference for 20° full depth involute teeth will be
12
14
18
24
Correct Answer :
C. 18
Related Questions
An alien bolt is
Self locking bolt
Same as stud
Provided with hexagonal depression in head
Used in high speed components
Coaxing is the procedure of increasing
Metal strength by cycling
Metal hardness by surface treatment
Metal resistance to corrosion by coating
Fatigue limit by overstressing the metal by successively increasing loadings
When spring index increases, the value of Wahl's stress factor
Increases linearly
Decreases linearly
Remains same
Increases exponentially
The dedendum is the radial distance from the
Pitch circle to the top of a tooth
Pitch circle to the bottom of a tooth
Top of a tooth to the bottom of a tooth
Addendum circle to the clearance circle
Fibrous fracture occurs in
Ductile material
Brittle material
Elastic material
Hard material
Machine screws are
Similar to small size tap bolts except that a greater variety of shapes of heads are available
Slotted for a screw driver and generally used with a nut
Used to prevent relative motion between two parts
Similar to stud
Which of the following statement is wrong?
The V-belt may be operated in either direction with tight side of the belt at the top or bottom
The V-belt drive is used with large centre distance
The power transmitted by V-belts is less than flat belts for the same coefficient of friction, arc of contact and allowable tension in the belts
The ratio of driving tensions in V-belt drive is more than flat belt drives
The included angle in unified of American National threads is
60°
55°
47°
29°
A double fillet welded joint with parallel fillet weld of length l and leg s is subjected to a tensile force P. Assuming uniform stress distribution, the shear stress in the weld is given by
√2P/s.l
P/2.s.l
P/√2.s.l
2P/s.l
When a bolt is subjected to shock loading, the resilience of the bolt should be considered in order to prevent breakage at the
Thread
Middle
Shank
Head
The efficiency of a square threaded screw is maximum if the helix angle is equal to (Where φ = Angle of friction)
90° - φ
45° - φ
45° - φ/2
45° + φ/2
When two nonintersecting and non-coplanar shafts are connected by gears, the arrangement is known as
Spur gearing
Helical gearing
Bevel gearing
Spiral gearing
I.S. specifies following total number of grades of tolerances
18
16
20
22
Eulers formula for a mild steel column is not valid if the slenderness ratio is
90
60
120
100
In cylindrical cams, the follower moves
In a direction perpendicular to the cam axis
In a direction parallel to the cam axis
In any direction irrespective of cam axis
Along the cam axis
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
If P1 and P2 are the tight and slack side tensions in the belt, then the initial tension Pi (according to Barth) will be equal to
[(√P1 + √P2)/2]²
P1 + P2
2 × (P1 + P2)
[2 × (P1 + P2)] + Pc Where Pc is centrifugal tension
Buttress threads are usually found on
Screw cutting lathes
Feed mechanisms
Spindles of bench vices
Railway carriage couplings
According to Unwin's formula, the relation between the diameter of rivet hole (d) and the thickness of plate (t) is given by (where d and t are in mm)
d = t
d = 1.6 t
d = 2t
d = 6t
In Vickers hardness testing, the pyramid indentor apex is
40°
122°
136°
152°
When a close coiled helical spring is compressed, its wire is subjected to
Tension
Shear
Compression
All of the above
A connecting rod is designed as a
Long column
Short column
Strut
All of these
Two rigid plates are clamped by means of bolt and nut with an initial force F. After tightening, a separating force P (P < F) is applied to the lower plate, which in turn acts on the nut. The tension in the both after this is
F + P
F P
P
F
In a gear, having Involute teeth, the normal to the Involute is a tangent to the
Base circle
Pitch circle
Addendum circle
Dedendum circle
When an open coiled helical compression spring is subjected to an axial compressive load, the maximum shear stress induced in the wire is (where D = Mean diameter of the spring coil, d = Diameter of the spring wire, K = Wahl's stress factor, and W = Axial compressive load on the spring)
(WD/ πd3) × K
(2WD/ πd3) × K
(4WD/ πd3) × K
(8WD/ πd3) × K
Endurance limit or fatigue limit is the maximum stress that a member can withstand for an infinite number of load applications without failure when subjected to
Dynamic loading
Static loading
Combined static and dynamic loading
Completely reversed loading
Antifriction bearings are
Sleeve bearings
Hydrodynamic bearings
Thin lubricated bearings
None of the above
The flank of the tooth is the
Surface of the top of the tooth
Surface of the tooth above the pitch surface
Width of the tooth measured along the pitch circle
Surface of the tooth below the pitch surface
A hot short metal is
Brittle when cold
Brittle when hot
Brittle under all conditions
Ductile at high temperature
Which of the following screw thread is used for power transmission in one direction only?
Square threads
Multiple threads
Acme threads
Buttress threads