Test: Design of Bearings - 2 - Mechanical Engineering MCQ

Starting friction is low in       

Average values of effective coefficients of friction for bearings are described below:  

Which one of the following sequences is correct?    

Which one of the following statements is correct?              

Antifriction bearings are 

The rolling element bearings are             

Ball bearings are provided with a cage 

Which one of the following statements is NOT true of rolling contact bearing?  

Consider the following statements about anti-friction bearings:  

1. They have low starting and low running friction at moderate speeds.

2. They have high resistance to shock loading.  

3. They can carry both radial and thrust loads.

4. Their initial cost is high.  

5. They can accommodate some amount of misalignments of shaft.

Of these statements  

If the load on a ball bearing is halved, its life:          

Which bearing is preferred for oscillating conditions? 

Match List-I with List-II and select the correct answer using the codes given below the lists: 

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

In sliding contact bearings, a positive pressure can be built up and a load supported by a fluid only by the use of a:             

Increase in values of which of the following results in an increase of the coefficient of friction in a hydrodynamic bearing?

1. Viscosity of the oil.

2. Clearance between shaft and bearing.  

3. Shaft speed.

Select the correct answer using the code given below:  

Consider tile following statements:                        

Radius of friction circle for a journal bearing depends upon

1. Coefficient of friction  

2. Radius of the journal  

3. Angular speed of rotation of the shaft

Which of the statements given above are correct?  

In a journal bearings, the radius of the friction circle increases with the increase in      

The bearing characteristic number in a hydrodynamic bearing depends on 

Assertion ( A): In equilibrium position, the journal inside a journal bearing remains floating on the oil film.              

Reason (R): In a journal bearing, the load on the bearing is perpendicular to the axis of the journal. 

A sliding contact bearing is operating under stable condition. The pressure developed in oil film is p when the journal rotates at N r.p.m. The dynamic viscosity of lubricant is μ and effective coefficient of friction between bearing and journal of diameter D is f. Which one of the following statements is correct for the bearing?  

 Consider the following pairs of types of bearings and applications:

1. Partial Journal bearing………………. Rail wagon axles        

2. Full journal bearing ………………….Diesel engine crank-shaft

3. Radial bearing ……………………….Combined radial and axial loads

Which of these pairs is/are correctly matched?  

Assertion (A): In anti-friction bearings, the frictional resistance is very low as the shaft held by it remains in floating condition by the hydrodynamic pressure developed by the lubricant.            

Reason (R): In hydrodynamic journal bearings, hydrodynamic pressure is developed because of flow of lubricant in a converging -diverging channel  

In an oil-lubricated journal bearing, coefficient of friction between the journal and the bearing. 

Which one of the following pair is correctly matched?        

Which one of the following types of bearings is employed in shafts of gearboxes of automobiles?    

Assertion (A): In hydrodynamic journal bearings, the rotating journal is held in floating condition by the hydrodynamic pressure developed in the lubricant.    

Reason (R): Lubricant flows in a converging-diverging channel.    

Deep groove ball bearings are used for 

In a journal bearing P = average bearing pressure, Z = absolute viscosity of the lubricant, N = rotational speed of the journal. The bearing characteristic number is given by 

Match List-I (Applications) with List-II (Choice of Bearings) and select the correct answer using the codes given below the lists: