MCQ Questions and Answers on Theory of Machines

Q.

For a spring controlled governor to be stable, the controlling force (F) is related to the radius (r) by the equation

A. F = ar−b

B. F = ar+b

C. F = ar

D. F = a/r−b

Discuss

Answer : Option:- A

Explanation :

Discuss here! No Explaination Available for These Question.

Q.

The sensitivity of an isochronous governor is

A. Zero

B. One

C. Two

D. Infinity

Discuss

Answer : Option:- D

Explanation :

A governor with infinite sensitiveness is called isochronous governor.

Q.

If φ is the friction angle, the efficiency of power screw is maximum when the lead angle is

A. π/2−φ/2

B. π/2−φ

C. π−φ/2

D. π−φ

Discuss

Answer : Option:- A

Explanation :

The efficiency of power screw is maximum when the lead angle is,
π/2−φ/2

Q.

A wheel of mass m and radius r is in accelerated rolling motion without slip under a steady axial torque T. If the coefficient of kinetic friction is µ the friction force from the ground on the wheel is

A. µmg

B. T/r

C. Zero

D. None of the above

Discuss

Answer : Option:- A

Explanation :

Discuss here! No Explaination Available for These Question.

Q.

A friction circle is drawn when a journal rotates in bearing. Its radius depends on the coefficient of friction and the

A. Magnitude of the forces on the journal

B. Angular velocity of the journal

C. Clearance between the journal and the bearing

D. Radius of the journal

Discuss

Answer : Option:- D

Explanation :

Discuss here! No Explaination Available for These Question.

Q.

Frictional torque for threads at mean radius while raising load is given by

A. WR.tan(φ−α)

B. WR.tan(φ+α)

C. WR.tanα

D. WR.tanφ

Discuss

Answer : Option:- B

Explanation :

Discuss here! No Explaination Available for These Question.

Q.

To ensure self-locking in a screw jack, it is essential that 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

Discuss

Answer : Option:- B

Explanation :

The angle of friction should always be more than the helix angle of the screw.

Q.

The maximum efficiency of a self-locking screw is

A. 50%

B. 70%

C. 75%

D. 80%

Discuss

Answer : Option:- A

Explanation :

The maximum efficiency of a self-locking screw is 50%.

Q.

In a collar thrust bearing, the number of collars have been doubled, while maintaining to coefficient of friction and axial thrust same. This will result in

A. Same frictional torque and same bearing pressure

B. Double frictional torque and half bearing pressure

C. Double frictional torque and same bearing pressure

D. Same frictional torque and half bearing pressure

Discuss

Answer : Option:- D

Explanation :

The thrust will be distributed into collars. Hence, the frictional torque will be reduced in each collar but overall for all the collars it will be the same.

Q.

In the multiple disc clutch, if there are 6 discs on the driving shaft and 5 discs on the driven shaft, then the number of pairs of contact surfaces will be equal to

A. 11

B. 12

C. 10

D. 22

Discuss

Answer : Option:- C

Explanation :

Given:
6 discs on the driving shaft and 5 discs on the driven shaft
i.e. n1=6, n2=5.
Thus,
Number of contact surface = n1+n2-1 = 6+5-1=10

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MCQ Questions and Answers on Theory of Machines

Q. For a spring controlled governor to be stable, the controlling force (F) is related to the radius (r) by the equation

Q. The sensitivity of an isochronous governor is

Q. If φ is the friction angle, the efficiency of power screw is maximum when the lead angle is

Q. A wheel of mass m and radius r is in accelerated rolling motion without slip under a steady axial torque T. If the coefficient of kinetic friction is µ the friction force from the ground on the wheel is

Q. A friction circle is drawn when a journal rotates in bearing. Its radius depends on the coefficient of friction and the

Q. Frictional torque for threads at mean radius while raising load is given by

Q. To ensure self-locking in a screw jack, it is essential that helix angle is

Q. The maximum efficiency of a self-locking screw is

Q. In a collar thrust bearing, the number of collars have been doubled, while maintaining to coefficient of friction and axial thrust same. This will result in

Q. In the multiple disc clutch, if there are 6 discs on the driving shaft and 5 discs on the driven shaft, then the number of pairs of contact surfaces will be equal to

Q.

For a spring controlled governor to be stable, the controlling force (F) is related to the radius (r) by the equation

Q.

The sensitivity of an isochronous governor is

Q.

If φ is the friction angle, the efficiency of power screw is maximum when the lead angle is

Q.

A wheel of mass m and radius r is in accelerated rolling motion without slip under a steady axial torque T. If the coefficient of kinetic friction is µ the friction force from the ground on the wheel is

Q.

A friction circle is drawn when a journal rotates in bearing. Its radius depends on the coefficient of friction and the

Q.

Frictional torque for threads at mean radius while raising load is given by

Q.

To ensure self-locking in a screw jack, it is essential that helix angle is

Q.

The maximum efficiency of a self-locking screw is

Q.

In a collar thrust bearing, the number of collars have been doubled, while maintaining to coefficient of friction and axial thrust same. This will result in

Q.

In the multiple disc clutch, if there are 6 discs on the driving shaft and 5 discs on the driven shaft, then the number of pairs of contact surfaces will be equal to