Related Questions

When the two elements of a pair have a surface contact when relative motion takes place and the surface of one element slides over the surface of the other, the pair formed is known as a
A lower pair
B higher pair
C self-closed pair
D force-closed pair
Pharmacists recently conducted a study with respect to the reasons their customers purchased eye drops to soothe eye dryness. Dry eyes were more frequently experienced by customers who wore contact lenses than by custorners who did not wear contact lenses. The pharmacists concluded that wearing contact lenses, by itself, can cause contact wearers to have dry eyes.
A An inherited condition can cause both weak eyesight and dry eyes
B Physical exertion causes dry eyes in many people who wear contact lenses.
C Most people who have dry eyes do not wear contact lenses.
D Most people who wear contact lenses do not have dry eyes.
The pair is known as a higher pair, when the relative motion between the elements of a pair is
A turning only
B sliding only
C rolling only
D partly turning and partly sliding
When the nature of contact between the elements of a pair is such that it can only slide relative to the other, the pair is known as a
A Screw pair
B Spherical pair
C Turning pair
D Sliding pair
When the nature of contact between the elements of a pair is such that one element can turn about the other by screw threads, the pair is known as a
A Screw pair
B Spherical pair
C Turning pair
D Sliding pair
When the two elements of a pair have __________ when in motion, it is said to a lower pair.
A Line or point contact
B Surface contact
C Body contact
D None of these
When the elements of a pair are kept in contact by the action of external forces, the pair is said to be a
A lower pair
B higher pair
C self-closed pair
D force-closed pair
Two circular dials of exactly the same size are mounted on a wall side by side in such a way that their perimeters touch at one point. Dial 1, which is on the left , spins clockwise around its center , and dial 2 , which is on the right spins counter clockwise around its center . (Assume that there is no friction at the point of contact between the dials.) Each dial is marked on its perimeter at three points that are at equale distances around the points arked ondial 1 are N, O, and P and the points marked on dial 2 are X, Y, and Z. If points O and Z are just meeting at the point of contact between the dials , and if dial 1 spins at the same speed as dial 2, what is the smallest number of revolutions of each dial that will bring O and Z together again?
A 1
B 2
C 3
D 4
The motion between a pair which takes place in __________ is known as incompletely constrained motion.
A One direction only
B Two directions only
C More than one direction
D None of these
If points P and Y are just meeting at the point of contact between the dials , and if dial 1 spins at exactly three time the speed of dial 2, which of the following pairs of points will be the next pair to meet at the point of contact?
A N and X
B N and Z
C O and Y
D P and Z

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