Top 150+ Solved Theory of Mechanics MCQ Questions Answer
Q. A flat foot step bearing 20 cm in diameter supports a load of 2500 kgf. The shaft is running at 420 rpm and the co-efficient is 0.09. The power lost in overcoming friction at the bearing, will be equal to ___.
a. 650 watt
b. 880 watt
c. 659.7 watt
d. 680.20 watt
Q. flat foot step bearing 20 cm in diameter supports a load of 2500 kgf. The shaft is running at 420 rpm and the co-efficient is 0.09. The power transmitted by the friction between the surface, will be equal to ___.
a. 493.875 watt
b. 880 watt
c. 659.7 watt
d. 680.20 watt
Q. A thrust bearing having collars of external and internal diameter as 40 cm and 20 cm respectively, carries an axial load of 3000 N. The co-efficient of friction is 0.09 and shaft runs at 420 rpm. The power lost in friction is to be determined. The corresponding value of friction torque would be ____.
a. 40.5 n-m
b. 42 n-m
c. 45.0 n-m
d. 48.5 n-m
Q. A flat foot step bearing 225 mm in diameter supports a load of 7500 N. If the co-efficient of friction is 0.09 and the shaft rotates at 60 rpm, calculate the power lost in frictional torque and frictional power in watts with uniform pressure is ___.
a. 50.62 n-m and 317.92 watt
b. 60.62 n-m and 320.92 watt
c. 57.68 n-m and 321.92 watt
d. 55.50 n-m and 410.12 watt
Q. Following are the details pertaining to thrust bearing 1) External and internal dia of contacting surfaces-320 mm and 200 mm resp. 2) Axial load-80 kN 3)Pr. Intensity-350 kN/m2 4) shaft speed-400 rpm 5)coefficient of friction-0.06 Calculate power lost in overcoming friction. the frictional torque and power lost in frictional
a. 600.35 nm and 26.60 kw
b. 630.30 nm and 28.40 kw
c. 635.08 nm and 26.60 kw
d. 650.52 nm and 27.35 kw
Q. A conical pivot supports a load of 20 kN, and its semicone angle is 41.81 degree. The friction coefficient is 0.06 and shaft runs at 200 rpm. The torque required to overcome friction and power lost in friction is
a. 135.20 nm and 2.93 kw
b. 125.40 nm and 2.93 kw
c. 130.35 nm and 2.53 kw
d. 135.36 nm and 2.83 kw
Q. The clutch is a device used______
a. to absorb frictional torque
b. to absorb frictional power
c. to transmit power from on shaft to another
d. all of the above
Q. Advantages of positive clutch is_____
a. they can be engaged at high speed
b. they cause for high speed application
c. shock and noise is there during engagement
d. due to no slip between contact surfaces no heat is generated
Q. Disadvantages of positive clutch is______
a. they can be engaged at high speed
b. they don’t provide positive engaged
c. shock and noise is there during engagement
d. due to no slip between contact surfaces no heat is generated
Q. Torque transmitted by friction clutch_______
a. is more on the assumption of uniform pressure as compared to uniform wear
b. is less on the assumption of uniform pressure as compared to uniform wear
c. is same on the assumption of uniform pressure and uniform wear
d. is more or less on the assumption of uniform pressure as compared to uniform wear depending upon material
Q. Frictional torque transmission through plate clutch is equivalent to____
a. conical pivot bearing
b. flat pivot bearing
c. trapezoidal pivot bearing
d. flat roller bearing