Question

Which of the following is a lower pair?
1. Piston and cylinder
2. Cam and follower
3. Belt drive
4. Gear

Answer 1

Correct Answer - Option 1 : Piston and cylinder

Explanation:

Lower pair:

• A pair is said to be a lower pair when the connection between two elements is through the area of contact.
  • Revolute Pair
  • Prismatic Pair (Piston and cylinder)
  • Screw Pair
  • Cylindrical Pair
  • Spherical Pair (Ball and socket)
  • Planar Pair, etc.

Higher pair:

• A higher pair is defined as one in which the connection between two elements has only a point or line of contact.
• A point contact takes place when spheres rest on a plane or curved surfaces (ball bearings) or between teeth of skew-helical gears, in roller bearings, between teeth of most of the gears, and in cam-follower motion.