24 + Mcqs in Design of Machine Elements

1.	A bevel gear consists of steel pinion and cast iron gear having pitch line velocity of 10 m/s. The maximum tangential force acting on the gear is 1500 N and face width is 40 mm. What is the dynamic load acting on this single stage bevel gear box if sum of errors on meshing teeth is 10 x 10 N/mm? (Use Buckingham's equation)
A.	4000.12 N
B.	4064.58 N
C.	2500.23 N
D.	2000.10 N
Answer» C. 2500.23 N

Discussion

2.	A bevel gear has pitch circle diameters of pinion and gear as 20 mm and 40 mm respectively. What is the face width of bevel gear?(m =module)
A.	17.5 m
B.	10 m
C.	7.45 m
D.	3.16 m
Answer» D. 3.16 m

Discussion

3.	A deep groove ball bearing rotating at 1200 r.p.m. is subjected to radial and an axial force of 2000 N and 1500 N respectively. What will be the basic dynamic capacity of bearing if 20,000 hours is the rating life? (Consider radial factor = 0.55, Thrust factor = 2 & application factor = 1.5?
A.	69.448 kN
B.	54.498 kN
C.	50.236 kN
D.	12.726 kN
Answer» B. 54.498 kN

Discussion

4.	If pressure angle is 22 and coefficient of friction is 0.05. What is the axial force acting on the worm gear designated as 1/40/10/5, if tangential force of 1200 N acts on it?
A.	1241.2 N
B.	2618.4 N
C.	7755.1 N
D.	7847.4 N
Answer» D. 7847.4 N

Discussion

5.	What is the axial force acting on a worm gear for a worm gear pair 1/40/9.5/10, if tangential and axial force of 6213 N and 9236 N act respectively on the worm? ( = 25 & = 0.04)
A.	6213 N
B.	9263 N
C.	3050 N
D.	Insufficient data
Answer» B. 9263 N

Discussion

6.	A straight bevel gear pinion rotates at 800 r.p.m transmitting power of 15 kW to the bevel gear. If pitch circle diameter of pinion is 130 mm and face width is 30 mm, then what is the tangential force acting on mean pitch circle?( = 23 & = 53)
A.	3461.53 N
B.	2988.12 N
C.	3027.30 N
D.	Insufficient data
Answer» D. Insufficient data

Discussion

7.	A gear box having surface area of 0.30 m has overall heat transfer coefficient of 23 W/m C,when a fan is mounted on worm shaft to circulate air on fins. What is the power transmitting capacity of a gear box based on thermal considerations, if temperature rise of lubricating oil is 50 C? (Assume = 6, = 22 & = 0.05)
A.	1.023 kW
B.	1.006 kW
C.	1.227 kW
D.	2.000 kW
Answer» C. 1.227 kW

Discussion

8.	What is the axial force acting on the pinion if a bevel gear transmits power of 20 kW with a mean pitch line velocity of 5 m/s? (Consider = 25 & = 15)
A.	1865 N
B.	1801.67 N
C.	971.37 N
D.	452.96 N
Answer» E.

Discussion

9.	What will be the static capacity of single-row deep groove ball bearing having 10 balls of 15 mm?(Assume K = 62 N/mm)
A.	25900 kN
B.	124 kN
C.	31.00 kN
D.	27.900 kN
Answer» E.

Discussion

10.	A flat belt transmits power of 20 kW when the velocity of the belt is 30 m/s. What will be the initial tension in the belt if230 N is the centrifugal tension in the belt and F / F =2.5?
A.	1007.77 N
B.	1000.2 N
C.	908.23 N
D.	896.15 N
Answer» B. 1000.2 N

Discussion

11.	What is the minimum face width required for a helical gear which has helix angle of 23 and normal module of 7?
A.	64.72
B.	56.28
C.	33.35
D.	8.74
Answer» B. 56.28

Discussion

12.	A helical gear transmits power of 2050 W and has helix angle of 25. If pitch line velocity is 15 m/s then what is the maximum tangential force acting on helical gear tooth? (Assume K = 1 & K = 1.2)
A.	113.88 N
B.	136 N
C.	164 N
D.	None of the above
Answer» D. None of the above

Discussion

13.	A helical gear made of plain carbon steel has face width 10 times the normal module. If number of teeth on pinion and gear are 20 and 60 respectively, then what will be the wear strength of helical gear? (Assume m = 5, BHN = 200 & = 24)
A.	5751.30 N
B.	5230.19 N
C.	6295.58 N
D.	6891.37 N
Answer» D. 6891.37 N

Discussion

14.	A helical gear has normal module of 6 mm. What is the transverse module if helix angle is 25?
A.	4.95 mm
B.	500 mm
C.	5.43 mm
D.	6.62 mm
Answer» E.

Discussion

15.	What is the axial pitch for helical gears if helix angle is 25 and normal module is 7?
A.	50.55 mm
B.	52.03 mm
C.	32.15 mm
D.	11.31 mm
Answer» C. 32.15 mm

Discussion

16.	Which of the following parameters in Petroff's equation f = 2 ( n/p) (r/c) is/are dimensionless?
A.	r/c
B.	n
C.	Both a. and b.
D.	None of the above
Answer» D. None of the above

Discussion

17.	Determine the Sommerfeld number considering the following data for hydrodynamic bearing?1. Diameter of bearing = 120 mm2. Bearing pressure = 5 N/mm3. Oil viscosity = 30 cP 4. Journal speed = 900 rpm5. Radial clearance = 150 microns
A.	0.2360
B.	0.0144
C.	0.0115
D.	0.0178
Answer» C. 0.0115

Discussion

18.	Lubricating oil of mass density 800 kg/mused in 360 hydrodynamic bearing has a flow rate of 6000 mm. Neglecting side leakage if temperature rises to 10 C and specific heat is 1.55 kJ/kg C, what is the rate of heat dissipated in the bearing?
A.	7.4 W
B.	236 W
C.	0.236 kW
D.	0.0744 kW
Answer» E.

Discussion

19.	A journal of 120 mm diameter rotates in a bearing at a speed of 1000 rpm. What is the power lost during friction if 8 kN radial load acts on the journal and coefficient of friction is 2.525 x 10?
A.	0.126 kW
B.	0.253 KW
C.	2.365 kW
D.	7.615 kW
Answer» B. 0.253 KW

Discussion

20.	A V-belt pulley has belt velocity 20 m/s and mass 0.7 kg per meter. If allowable tension in the belt is 600 N then what will be the power transmitting capacity of belt? (Assume = 0.5 & = 2.5 rad)
A.	3.75 kW
B.	3.2 kW
C.	4.5 kW
D.	5.23 kW
Answer» D. 5.23 kW

Discussion

21.	If ( x Y) > ( x Y) then ________ is designed for bending.
A.	pinion
B.	gear
C.	both a. and b.
D.	none of the above
Answer» C. both a. and b.

Discussion

22.	What is the deformation or dynamic factor if sum of errors on meshing teeth of steel pinion and gear is 32 x 10 mm?
A.	284.8 N/mm
B.	300.23 N/mm
C.	320.5 N/mm
D.	368 N/mm
Answer» E.

Discussion

23.	Spiral gears are used only if the axes of two shafts are non-intersecting, non-parallel and __________.
A.	perpendicular
B.	parallel
C.	non-perpendicular
D.	none of the above
Answer» D. none of the above

Discussion

24.	A V-belt pulley transmits power to flat belt pulley. If the coefficient of friction is 0.25 then which pulley governs the design? ( = 21 & = 0.2)
A.	Flat pulley
B.	V-belt pulley
C.	Both a. and b.
D.	None of the above
Answer» B. V-belt pulley

Discussion

Explore topic-wise MCQs in Mechanical Engineering (MCQ) questions and answers.

A bevel gear has pitch circle diameters of pinion and gear as 20 mm and 40 mm respectively. What is the face width of bevel gear?(m =module)

A deep groove ball bearing rotating at 1200 r.p.m. is subjected to radial and an axial force of 2000 N and 1500 N respectively. What will be the basic dynamic capacity of bearing if 20,000 hours is the rating life? (Consider radial factor = 0.55, Thrust factor = 2 & application factor = 1.5?

If pressure angle is 22 and coefficient of friction is 0.05. What is the axial force acting on the worm gear designated as 1/40/10/5, if tangential force of 1200 N acts on it?

What is the axial force acting on a worm gear for a worm gear pair 1/40/9.5/10, if tangential and axial force of 6213 N and 9236 N act respectively on the worm? ( = 25 & = 0.04)

A straight bevel gear pinion rotates at 800 r.p.m transmitting power of 15 kW to the bevel gear. If pitch circle diameter of pinion is 130 mm and face width is 30 mm, then what is the tangential force acting on mean pitch circle?( = 23 & = 53)

What is the axial force acting on the pinion if a bevel gear transmits power of 20 kW with a mean pitch line velocity of 5 m/s? (Consider = 25 & = 15)

What will be the static capacity of single-row deep groove ball bearing having 10 balls of 15 mm?(Assume K = 62 N/mm)

A flat belt transmits power of 20 kW when the velocity of the belt is 30 m/s. What will be the initial tension in the belt if230 N is the centrifugal tension in the belt and F / F =2.5?

What is the minimum face width required for a helical gear which has helix angle of 23 and normal module of 7?

A helical gear transmits power of 2050 W and has helix angle of 25. If pitch line velocity is 15 m/s then what is the maximum tangential force acting on helical gear tooth? (Assume K = 1 & K = 1.2)

A helical gear made of plain carbon steel has face width 10 times the normal module. If number of teeth on pinion and gear are 20 and 60 respectively, then what will be the wear strength of helical gear? (Assume m = 5, BHN = 200 & = 24)

A helical gear has normal module of 6 mm. What is the transverse module if helix angle is 25?

What is the axial pitch for helical gears if helix angle is 25 and normal module is 7?

Which of the following parameters in Petroff's equation f = 2 ( n/p) (r/c) is/are dimensionless?

Determine the Sommerfeld number considering the following data for hydrodynamic bearing?1. Diameter of bearing = 120 mm2. Bearing pressure = 5 N/mm3. Oil viscosity = 30 cP 4. Journal speed = 900 rpm5. Radial clearance = 150 microns

Lubricating oil of mass density 800 kg/mused in 360 hydrodynamic bearing has a flow rate of 6000 mm. Neglecting side leakage if temperature rises to 10 C and specific heat is 1.55 kJ/kg C, what is the rate of heat dissipated in the bearing?

A journal of 120 mm diameter rotates in a bearing at a speed of 1000 rpm. What is the power lost during friction if 8 kN radial load acts on the journal and coefficient of friction is 2.525 x 10?

A V-belt pulley has belt velocity 20 m/s and mass 0.7 kg per meter. If allowable tension in the belt is 600 N then what will be the power transmitting capacity of belt? (Assume = 0.5 & = 2.5 rad)

If ( x Y) > ( x Y) then ________ is designed for bending.

What is the deformation or dynamic factor if sum of errors on meshing teeth of steel pinion and gear is 32 x 10 mm?

Spiral gears are used only if the axes of two shafts are non-intersecting, non-parallel and __________.

A V-belt pulley transmits power to flat belt pulley. If the coefficient of friction is 0.25 then which pulley governs the design? ( = 21 & = 0.2)