For the given statements: I. Mating spur gear teeth is an example of a higher pair. II. A revolute joint is an example of a lower pair. Indicate the correct answer.

Both I and II are false
I is true and II is false
I is false and II is true
Both I and II are true

Correct answer: I is false and II is true

Solution

Mating spur gear teeth form a higher pair because the contact is along a line/point, not over a surface. A revolute joint (pin joint) is a lower pair because it has surface contact and allows relative rotation.

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