Machine Kinematics Multiple Choice Questions on “Comparison Between Involute and Cycloidal Gears”.
1. The velocity of sliding _____________ the distance of the point of contact from the pitch point.
a) is directly proportional to
b) is inversaly proportional to
c) is equal to cosɸ multiplied by
d) does not depend upon
Answer: a
Clarification: The velocity of sliding is the velocity of one tooth relative to its mating tooth along the common tangent at the point of contact.
2. In involute gears, the pressure angle is
a) dependent on the size of teeth
b) dependent on the size of gears
c) always constant
d) always variable
Answer: c
Clarification: None
3. In full depth 140 involute system, the smallest number of teeth in a pinion which meshes with rack without interference is
a) 12
b) 16
c) 25
d) 32
Answer: d
Clarification: The minimum number of teeth on the pinion in order to avoid interference for 14.50 full depth involute are 32 and for 200 full depth involute teeth are 18.
4. The pressure angle for involute gears depends upon the size of teeth.
a) True
b) False
Answer: b
Clarification: In a gear drive, the shape of the tooth depends upon the pressure angle.
5. The contact ratio is given by
a) Length of the path of approach/Circular pitch
b) Length of the path of recess/Circular pitch
c) Length of the arc of contact/Circular pitch
d) Length of the arc of approach/cosɸ
Answer: c
Clarification: None
6. For an involute gear, the ratio of base circle radius and pitch circle radius is equal to
a) sinɸ
b) cosɸ
c) secɸ
d) cosecɸ
Answer: b
Clarification: None
7. Which of the following statement is correct for gears?
a) The addendum is less than the dedendum
b) The pitch circle diameter is the product of module and number of teeth
c) The contact ratio means the number of pairs of teeth in contact
d) All of the mentioned
Answer: d
Clarification: None
8. In a gear having involute teeth, the normal to the involute is a tangent to the
a) pitch circle
b) base circle
c) addendum circle
d) dedendum circle
Answer: b
Clarification: Addendum circle is the circle drawn through the top of the teeth and is concentric with the pitch circle.
Dedendum circle is the circle drawn through the bottom of the teeth. It is also called root circle.
Pitch circle is an imaginary circle which by pure rolling action, would give the same motion as the actual gear.
9. The centre distance between two meshing involute gears is equal to
a) sum of base circle radii/cosɸ
b) difference of base circle radii/cosɸ
c) sum of pitch circle radii/cosɸ
d) difference of pitch circle radii/cosɸ
Answer: a
Clarification: None
10. When the tip of a tooth undercuts the root on its mating gear, it is known as interference.
a) True
b) False
Answer: a
Clarification: None