SECTION-4

##### Q11. The thickness (t) of a thick cylinder according to Lame’s theory is equal to

$(a) \frac{d}{2}\left[\sqrt{\left(\frac{f+p}{f-p}\right)}-1\right]$

$\text { (b) } \frac{d}{2}[\sqrt{(f+p)}-1]$

$\text { (c) } \frac{d}{2}\left[\sqrt{\frac{f-p}{f+p}}-1\right]$

$\text { (d) } \frac{d}{2} \sqrt{(f-p)} \text {. }$

where f = Hoop stress, d = Internal diameter of the cylinder, and
p = Internal fluid pressure.

Ans:$(a) \frac{d}{2}\left[\sqrt{\left(\frac{f+p}{f-p}\right)}-1\right]$

##### Q12. The maximum hoop stress in case of a thick cylinder is equal to

$(a) \frac{p\left(d_{o}^{2}-d_{i}^{2}\right)}{d_{0}^{2}+d_{i}^{2}}$

$\text { (b) } \frac{p\left(d_{o}^{2}+d_{i}^{2}\right)}{d_{o}^{2}-d_{i}^{2}}$

$\text { (c) } \frac{p\left(d_{0}^{2}-d_{i}^{2}\right)}{d_{0}^{2}}$

$\text { (d) } \frac{p\left(d_{0}^{2}+d_{i}^{2}\right)}{d_{i}^{2}} .$

where do = Outer diameter of cylinder, di = Inner diameter of cylinder, and
p = Internal fluid pressure.

Ans:$\text { (b) } \frac{p\left(d_{o}^{2}+d_{i}^{2}\right)}{d_{o}^{2}-d_{i}^{2}}$

##### Q13. The frictional torque transmitted by a disc clutch, considering uniform pressure for a single friction surface is equal to

$(a) \frac{2}{3} \mu W \frac{\left(r_{1}^{2}-r_{2}^{2}\right)}{\left(r_{1}^{3}-r_{2}^{3}\right)}$

$\text { (b) } \frac{2}{3} \mu W \frac{\left(r_{1}^{3}-r_{2}^{3}\right)}{\left(r_{1}^{2}-r_{2}^{2}\right)}$

$\text { (c) } \frac{1}{2} \pi W\left(r_{1}-r_{2}\right)$

$\text { (d) } \frac{1}{2} \pi W\left(r_{1}+r_{2}\right) \text {. }$

where W = Axial thrust with which the contact surfaces are held together,
r1 = Outer radius of the plate, and r2 = Inner radius of the plate.

Ans:$\text { (b) } \frac{2}{3} \mu W \frac{\left(r_{1}^{3}-r_{2}^{3}\right)}{\left(r_{1}^{2}-r_{2}^{2}\right)}$

##### Q14. In the links of suspension chains

(a) a cotter joint is used
(b) a knuckle joint is used
(c) both are used
(d) none is used.

Ans:(b) a knuckle joint is used

##### Q15. A cotter joint may fail due to

(a) shearing
(b) bending
(c) crushing
(d) all of the above.

Ans:(d) all of the above.

##### Q16. A knuckle joint may fail due to

(a) shearing
(b) bending
(c) crushing
(d) all of the above.

Ans:(d) all of the above.

##### Q17. When the horse power transmitted is maximum, the centrifugal tension is equal to

(a) one-half of the maximum tension
(b) one-third to the maximum tension
(c) one-fourth of the maximum tension
(d) three times the maximum tension.

Ans:(b) one-third to the maximum tension

##### Q18. The power transmitted from the shaft by the key will be 100% if the shearing strength of the key is

(a) half the torsional shear strength of the shaft
(b) 80% of the torsional shear strength of the shaft
(c) 90% of the torsional shear strength of the shaft
(d) equal to the torsional shear strength of the shaft.

Ans:(d) equal to the torsional shear strength of the shaft.

(a) D
(b) 1.25D
(c) 1.571D
(d) 1.75D.

Ans:(c) 1.571D

##### Q20. Which of the following couplings is used to connect two shafts which are parallel and in line?

(a) muff-coupling
(b) split-coupling
(c) flange-coupling
(d) any one of the above

Ans:(d) any one of the above

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##### Read More Sections of Machine Design

Each section contains maximum 80 Questions. To practice more questions visit other sections.

Machine Design MCQ – Section-1

Machine Design MCQ – Section-2

Machine Design MCQ – Section-3

Machine Design MCQ – Section-4

Machine Design MCQ – Section-5

Machine Design MCQ – Section-6

Machine Design MCQ – Section-7