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This section includes 11 Mcqs, each offering curated multiple-choice questions to sharpen your Machine Kinematics knowledge and support exam preparation. Choose a topic below to get started.
1. |
A screw jack has square threads and the lead angle of the thread is α. The screw jack will be self locking when the coefficient of friction (μ) is |
A. | μ > tan α |
B. | μ = sin α |
C. | μ = cot α |
D. | μ = cosec α |
Answer» B. μ = sin α | |
2. |
If α denotes the lead angle and φ, the angle of friction, then the efficiency of the screw is written as |
A. | tan(α − φ)/tanα |
B. | tanα/tan (α − φ) |
C. | tan(α + φ)/tanα |
D. | tanα/tan (α + φ) |
Answer» E. | |
3. |
WHILE_DESIGNING_A_SCREW_IN_A_SCREW_JACK_AGAINST_BUCKLING_FAILURE,_THE_END_CONDITIONS_FOR_THE_SCREW_ARE_TAKEN_AS?$ |
A. | both ends fixed |
B. | both ends hinged |
C. | one end fixed and other end hinged |
D. | one end fixed and other end free. |
Answer» E. | |
4. |
The_load_cup_of_a_screw_jack_is_made_separate_from_the_head_of_the_spindle_to$ |
A. | enhance the load carrying capacity of the jack |
B. | reduce the effort needed for lifting the working load |
C. | reduce the value of frictional torque required to be countered for lifting the load |
D. | prevent the rotation of load being lifted |
Answer» E. | |
5. |
A screw is said to be self locking screw, if its efficiency is |
A. | less than 50% |
B. | more than 50% |
C. | equal to 50% |
D. | none of the mentioned |
Answer» B. more than 50% | |
6. |
To ensure self locking in a screw jack, it is essential that the helix angle is |
A. | larger than friction angle |
B. | smaller than friction angle |
C. | equal to friction angle |
D. | such as to give maximum efficiency in lifting |
Answer» C. equal to friction angle | |
7. |
A screw jack has square threads and the lead angle of the thread is α. The screw jack will be self locking when the coefficient of friction (μ) is$ |
A. | μ > tan α |
B. | μ = sin α |
C. | μ = cot α |
D. | μ = cosec α |
Answer» B. ‚âà√≠¬¨‚à´ = sin ‚âà√≠¬¨¬± | |
8. |
If α denotes the lead angle and φ, the angle of friction, then the efficiency of the screw is written as$ |
A. | tan(α − φ)/tanα |
B. | tanα/tan (α − φ) |
C. | tan(α + φ)/tanα |
D. | tanα/tan (α + φ) |
Answer» E. | |
9. |
Screws used for power transmission should have |
A. | low efficiency |
B. | high efficiency |
C. | very fine threads |
D. | strong teeth |
Answer» C. very fine threads | |
10. |
Multiple threads are used to secure |
A. | low efficiency |
B. | high efficiency |
C. | high load lifting capacity |
D. | high mechanical advantage |
Answer» C. high load lifting capacity | |
11. |
Which of the following screw thread is adopted for power transmission in either direction? |
A. | Acme threads |
B. | Square threads |
C. | Buttress threads |
D. | Multiple threads |
Answer» C. Buttress threads | |