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- Question
In a screw jack, the effort required to lower the load W is given by
Options- A. P = W tan(? - ?)
- B. P = W tan(? + ?)
- C. P = W tan(? - ?)
- D. P = W cos(? + ?)
- Correct Answer
- P = W tan(? - ?)
- 1. The pair is known as a higher pair, when the relative motion between the elements of a pair is
Options- A. turning only
- B. sliding only
- C. rolling only
- D. partly turning and partly sliding Discuss
- 2. The static friction
Options- A. bears a constant ratio to the normal reaction between the two surfaces
- B. is independent of the area of contact, between the two surfaces
- C. always acts in a direction, opposite to that in which the body tends to move
- D. all of the above Discuss
- 3. When the relation between the controlling force (Fc) and radius of rotation (r) for a spring controlled governor is Fc = ar + b, then the governor will be
Options- A. stable
- B. unstable
- C. isochronous
- D. none of these Discuss
- 4. The gear train usually employed in clocks is a
Options- A. simple gear train
- B. reverted gear train
- C. sun and planet gear
- D. differential gear Discuss
- 5. If ?/?n = 2, where co is the frequency of excitation and ?n is the natural frequency of vibrations, then the transmissibility of vibration will the
Options- A. 0.5
- B. 1
- C. 1.5
- D. 2 Discuss
- 6. When the connection between the two elements is such that only required kind of relative motion occurs, it is known as self-closed pair.
Options- A. Right
- B. Wrong Discuss
- 7. In a circular arc cam with roller follower, the acceleration in any position of the lift will depend only upon
Options- A. total lift, total angle of lift, minimum radius of cam and cam speed
- B. radius of circular arc, cam speed, location of centre of circular arc and roller diameter
- C. mass of cam follower linkage, spring stiffness and cam speed
- D. total lift, centre of gravity of the cam and cam speed Discuss
- 8. The two links OA and OB are connected by a pin joint at O. If the link OA turns with angular velocity ?1 rad/s in the clockwise direction and the link OB turns with angular velocity ?2 rad/s in the clockwise direction, then the rubbing velocity at the pin joint O is (where r = Radius of the pin at O)
Options- A. ?1.?2.r
- B. ( ?1 - ?2)r
- C. ( ?1 + ?2)r
- D. ( ?1 - ?2)2r Discuss
- 9. The frequency of damped vibrations with viscous damping is __________ the frequency of undamped vibrations.
Options- A. more than
- B. less than
- C. same as Discuss
- 10. In order to balance the reciprocating masses,
Options- A. primary forces and couples must be balanced
- B. secondary forces and couples must be balanced
- C. both (a) and (b)
- D. none of these Discuss
Theory of machines problems
Search Results
Correct Answer: partly turning and partly sliding
Correct Answer: all of the above
Correct Answer: unstable
Correct Answer: reverted gear train
Correct Answer: 1
Correct Answer: Right
Correct Answer: total lift, total angle of lift, minimum radius of cam and cam speed
Correct Answer: ( ?1 - ?2)r
Correct Answer: less than
Correct Answer: both (a) and (b)
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