# Machine Design Questions and Answers – Bevel Gears

«
»

This set of Machine Design Multiple Choice Questions & Answers (MCQs) focuses on “Bevel Gears”.

1. There are ____ common types of bevel gears.
a) 1
b) 2
c) 3
d) 4

Explanation: Spiral and straight.

2. Straight bevel gears are easy to design and manufacture and give reasonably good service with quieter operation.
a) True
b) No, noise problem
c) No, vibration problem
d) None of the listed

Explanation: They produce a lot of noise while working.

3. Which of the following creates smoother motion?
a) Straight bevel gears
b) Spiral bevel gears
c) Equal for straight and spiral
d) None of the mentioned

Explanation: Spiral bevel gear has smooth engagement which results in quieter operation.
Note: Join free Sanfoundry classes at Telegram or Youtube

4. When the pitch angle is greater than 90⁰, it is called external bevel gear.
a) True
b) Internal
c) Helical
d) Herringbone

Explanation: For external bevel gear, pitch angle is less than 90⁰.

5. For crown bevel gear, pitch angle is
a) <90
b) =90
c) >90
d) None of the listed

Explanation: Crown gears are characterised by pitch angle of 90⁰.

6. If pitch angle is >90, the bevel gear is?
a) Internal
b) External
c) Crown
d) Static

Explanation: Nomenclature.

7. Miter gears are the bevel gears mounted on shaft which are intersecting at angle greater than 90.
a) True
b) False

Explanation: The shafts which are intersecting at 90.

8. Crown gears having a pitch angle of 90⁰ are mounted on shafts intersecting at an angle
a) =90
b) <90
c) >90
d) None of the listed

Explanation: Application of crown gear according to its structure.

9. Which of the following are characteristics of skew bevel gears?
a) Straight teeth
b) Mounted on parallel shafts
c) Mounted on intersecting shafts
d) All of the mentioned

Explanation: They are used in non-parallel and non-intersecting shafts.

10. Hypoid gears are based on surfaces that are paraboloids of revolution.
a) True
b) False

Explanation: They are hyperboloids of revolution.

11. When two hyperboloids are rotated, the resulting motion is
a) Sliding
b) Turning
c) Combination of turning and sliding
d) Rotary

Explanation: There is turning as well as sliding motion.

12. In hypoid bevel gears, shafts may continue past each other.
a) True
b) False

Explanation: Offset of the shaft is quite considerable in case of hypoid gears.

13. Hypoid gears have the following characteristics.
a) Curved teeth
b) Mounted on non -parallel non intersecting shafts
c) Efficiency of 97%
d) All of the mentioned

Explanation: It has curved teeth and are mounted on non-parallel non intersecting shafts with efficiency of 96-98%.

14. Zerol gears are straight bevel gears with zero spiral angle.
a) True
b) False

Explanation: They happen to fall in the category of spiral bevel gears.

15. Zerol gears give lesser contact ratio.
a) True
b) No, larger contact ratio
c) Zero contact
d) None of the listed