MCQs on System of Gear Tooth
1 - Question
There are ____ standard systems for the shape of gear teeth.
a) 1
b) 2
c) 3
d) 4
View Answer
Answer: c
Explanation: 14.5⁰ full depth involute system, 20⁰ full depth involute system and 20⁰ stub involute system.
2 - Question
When the number of teeth reaches infinity, circle radius approaches infinity the gear becomes an infinite loop.
a) True
b) False
View Answer
Answer: b
Explanation: It becomes a rack with straight sided teeth.
3 - Question
Which of the following statements are not true?
a) Increasing pressure angle improves the tooth strength
b) Contact duration is decreased with increase in pressure angle
c) 20⁰ pressure angle has quieter operation then 14.5⁰
d) All of the statements are true
View Answer
Answer: c
Explanation: Lower the pressure angle, quieter is the operation. Lower the pressure angle, lower is the breadth of the tooth at root.
4 - Question
20⁰ stub involute system have comparatively smaller interference.
a) True
b) False
View Answer
Answer: a
Explanation: They have shorter addendum and shorter dedendum.
5 - Question
Which of the following have stronger teeth?
a) Stub teeth
b) Full depth teeth
c) Both have equal strength
d) Can’t be determined
View Answer
Answer: a
Explanation: Smaller moment arm of bending force leads to stronger stub teeth.
6 - Question
As the module increases, index of size of gear decreases.
a) True
b) False
View Answer
Answer: b
Explanation: Module is the measure of size of index of the gear tooth.
7 - Question
Crowning is an abrasive process that debars the gear strength.
a) True
b) False
View Answer
Answer: b
Explanation: Crowningis used to strengthen the tooth.
8 - Question
Inaccuracies in tooth profile lead to concentration of pressure on the middle of tooth. crowning.
a) True
b) False
View Answer
Answer: b
Explanation: Inaccuracies lead to shift of pressure at the end of tooth which can be improved by
9 - Question
A pair of spur gears consist of 25 teeth pinion meshing with a 115 teeth gear. The module is 5mm. Calculate the centre distance.
a) 280mm
b) 269mm
c) 350mm
d) 305mm
View Answer
Answer: a
Explanation: C=m(z(p)+z(g))/2.
10 - Question
A pair of spur gears consist of 25 teeth pinion meshing with a 115 teeth gear. The module is 5mm. Calculate pitch circle diameter of the pinion.
a) 95mm
b) 105mm
c) 115mm
d) 125mm
View Answer
Answer: d
Explanation: D=5×25.
11 - Question
A pair of spur gears consist of 25 teeth pinion meshing with a 115 teeth gear. The module is 5mm. Calculate the pitch circle diameter of the gear.
a) Cannot be determined
b) 31mm
c) 475mm
d) 575mm
View Answer
Answer: d
Explanation: D=5×115.
12 - Question
A pair of spur gears consist of 25 teeth pinion meshing with a 115 teeth gear. The module is 5mm. Calculate the addendum.
a) None of the listed
b) 4.75mm
c) 5.25mm
d) 5mm
View Answer
Answer: d
Explanation: H=m=5mm.
13 - Question
A pair of spur gears consist of 25 teeth pinion meshing with a 115 teeth gear. The module is 5mm. Calculate the dedendum.
a) 4.75mm
b) 5mm
c) 6.25mm
d) 6.68mm
View Answer
Answer: c
Explanation: H=1.25xm=1.25x5mm.
14 - Question
A pair of spur gears consist of 25 teeth pinion meshing with a 115 teeth gear. The module is 5mm. Calculate the tooth thickness.
a) 6.23mm
b) 5.44mm
c) 7.854mm
d) 8.16mm
View Answer
Answer: c
Explanation: T=1.5708xm=1.5708x5mm.
15 - Question
A pair of spur gears consist of 25 teeth pinion meshing with a 115 teeth gear. The module is 5mm. Calculate the bottom clearance.
a) None of the listed
b) 1.75mm
c) 2.5mm
d) 1.25mm
View Answer
Answer: d
Explanation: C=0.25m=0.25x5mm.