MCQs on Keys
1 - Question
A force 2P is acting on the double transverse fillet weld. Leg of weld is h and length l. Determine the shear stress in a plane inclined at θ with horizontal.
a) PSinθ(Sinθ+Cosθ)/hl
b) P(Sinθ+Cosθ)/hl
c) Pcosθ(Sinθ+Cosθ)/hl
d) None of the listed
View Answer
Answer: a
Explanation: F=PSinθ and width=h/(Sinθ+Cosθ).
2 - Question
Maximum shear stress in transverse fillet weld of leg h and length l is
a) P/hl
b) 1.21P/hl
c) P/1.21hl
d) None of the listed
View Answer
Answer: b
Explanation: τ= PSinθ(Sinθ+Cosθ)/hl, by maximising it θ=67.5’ and hence find corresponding τ.v
3 - Question
A sunk key fits in the keyway of the _____ only.
a) Hub
b) Sleeve
c) Both hub and sleeve
d) Neither hub nor sleeve
View Answer
Answer: a
Explanation: Sunk key fits halfway in the hub and halfway in the shaft.
4 - Question
Hollow saddle key is superior to flat saddle key as far as power transmitting capability is concerned.
a) True
b) False
View Answer
Answer: b
Explanation: The resistance to slip in case of flat key is more.
5 - Question
Saddle key is more suitable than sunk key for heavy duty applications.
a) True
b) False
View Answer
Answer: b
Explanation: In sunk key, relative motion is also prevented by shear resistance of sunk key and hence sunk key is recommended.
6 - Question
The main advantage of sunk key is that it is a _____ drive.
a) Positive
b) Negative
c) Neutral
d) None of the listed
View Answer
Answer: a
Explanation: Sunk key is a positive drive and no slip occurs.
7 - Question
Woodruff key permits _____ movement b/w shaft and the hub.
a) Axial
b) Radial
c) Eccentric
d) None of the listed
View Answer
Answer: b
Explanation: Woodruff key is a sunk key and doesn’t permit axial moment.
8 - Question
Determine the length of kennedy key required to transmit 1200N-m and allowable shear in the key is 40N/mm². The diameter of shaft and width of key can be taken as 40mm and 10mm respectively.
a) 49mm
b) 36mm
c) 46mm
d) 53mm
View Answer
Answer: d
Explanation: l=M/[dbτ√2].
9 - Question
Splines are keys.
a) True b) False
View Answer
Answer: a
Explanation: Splines are keys made with shafts.
10 - Question
Involute splines have stub teeth with a pressure angle of ___
a) 30
b) 45
c) 60
d) Can’t be determined
View Answer
Answer: b
Explannation: Pressure angle is 30’ and not 60’.