Machine Design MCQs

Question 1

Two closely coiled helical springs with stiffness k1 and k2 respectively are connected in series. The stiffness of an equivalent spring is given by

Accepted Answer

$$\frac{{{{	ext{k}}_1}{{	ext{k}}_2}}}{{{{	ext{k}}_1} + {{	ext{k}}_2}}}$$

Answer

$$\frac{{{{	ext{k}}_1} - {{	ext{k}}_2}}}{{{{	ext{k}}_1} + {{	ext{k}}_2}}}$$

Answer

$$\frac{{{{	ext{k}}_1} + {{	ext{k}}_2}}}{{{{	ext{k}}_1}{{	ext{k}}_2}}}$$

Answer

$$\frac{{{{	ext{k}}_1} - {{	ext{k}}_2}}}{{{{	ext{k}}_1}{{	ext{k}}_2}}}$$

Question 2

For same pulley diameters, center distance, belt speed and belt and pulley materials,

Accepted Answer

Crossed belt drive transmits more power than open belt drive

Answer

Open belt drive transmits more power than crossed belt drive

Answer

Open and crossed belt drives transmit same power

Answer

Power transmission does not depend upon open and crossed types of constructions

Question 3

Two shafts will have equal strength, if

Accepted Answer

Twisting moment of both the shafts is same

Answer

Diameter of both the shafts is same

Answer

Angle of twist of both the shafts is same

Answer

Material of both the shafts is same

Question 4

The draw of cotter need not exceed

Accepted Answer

3 mm

Answer

5 mm

Answer

10 mm

Answer

20 mm

Question 5

For a bevel gear having the pitch angle $$	heta $$, the ratio of formative number of teeth (TE) to actual number of teeth (T) is

Accepted Answer

$$\frac{1}{{\cos 	heta }}$$

Answer

$$\frac{1}{{\sin 	heta }}$$

Answer

$$\frac{1}{{	an 	heta }}$$

Answer

$$\sin 	heta \cos 	heta $$

Question 6

Crushing resistance required to crush the rivet per pitch length is

Accepted Answer

$${	ext{ndt}}{\sigma _{	ext{c}}}$$

Answer

$${	ext{pd}}{\sigma _{	ext{c}}}$$

Answer

$${	ext{pt}}{\sigma _{	ext{c}}}$$

Answer

$$\left( {{	ext{p}} - {	ext{d}}} ight){	ext{t}}{\sigma _{	ext{c}}}$$

Question 7

Tearing resistance required to tear off the plate per pitch length is (where p = Pitch of rivets, d = Dia. of rivet hole and $${\sigma _{	ext{t}}}$$ = Permissible tensile stress for plate material)

Accepted Answer

$$\left( {{	ext{p}} - {	ext{d}}} ight){	ext{t}}{\sigma _{	ext{t}}}$$

Answer

$${	ext{pd}}{\sigma _{	ext{t}}}$$

Answer

$${	ext{pt}}{\sigma _{	ext{t}}}$$

Answer

$$\left( {{	ext{p}} - {	ext{d}}} ight){\sigma _{	ext{t}}}$$

Question 8

Which of the following welded joint is designed for shear strength?

Accepted Answer

Parallel fillet welded joint

Answer

Transverse fillet welded joint

Answer

Butt welded joint

Answer

All of these

Question 9

Fibrous fracture occurs in

Accepted Answer

Ductile material

Answer

Brittle material

Answer

Elastic material

Answer

Hard material