Engineering  :: Engineering Materials
            
            
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                | 211.  | 
Chromium when added as an alloying element to steels |  
 
 
                
			 
				
					
				| A. | 
                 Softens the material | 
				 				 B. | 
                 Refines the grain structure | 
				  
				 
				 				 | C. | 
                 Increases corrosion resistance | 
				 				 D. | 
                 Increases red hardness | 
				 				  
				 
				 				  
				    | E. | 
                    Improves mechanical properties | 
					
					    | 
                   | 
				 
				  
				 				 
				  
                    
                        
                        
                            Answer: Option C  
                            Explanation:  
                                
                         
                     
                    
                    
                    
                    
                    
                    
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                | 212.  | 
The behavious of visco-elastic material is  |  
 
 
                
			 
				
					
				| A. | 
                 Time dependent | 
				 				 B. | 
                 Independent of time | 
				  
				 
				 				 | C. | 
                 Elastic | 
				 				 D. | 
                 Plastic | 
				 				  
				 
				 				  
				    | E. | 
                    Ductile | 
					
					    | 
                   | 
				 
				  
				 				 
				  
                    
                        
                        
                            Answer: Option C  
                            Explanation:  
                                
                         
                     
                    
                    
                    
                    
                    
                    
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                | 213.  | 
Visco-elastic behaviour is common in |  
 
 
                
			 
				
					
				| A. | 
                 Crystalline materials | 
				 				 B. | 
                 Non-crystalline solids | 
				  
				 
				 				 | C. | 
                 Non-crystalline organic polymers | 
				 				 D. | 
                 Plastics | 
				 				  
				 
				 				  
				    | E. | 
                    Rubber | 
					
					    | 
                   | 
				 
				  
				 				 
				  
                    
                        
                        
                            Answer: Option A  
                            Explanation:  
                                
                         
                     
                    
                    
                    
                    
                    
                    
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                | 214.  | 
An elastic behaviour of materials is expressed in terms of |  
 
 
                
			 
				
					
				| A. | 
                 Stress strain curve | 
				 				 B. | 
                 Relaxation time | 
				  
				 
				 				 | C. | 
                 Adiabatic time | 
				 				 D. | 
                 Isothermal time | 
				 				  
				 
				 				  
				    | E. | 
                    Hysteresis loop area | 
					
					    | 
                   | 
				 
				  
				 				 
				  
                    
                        
                        
                            Answer: Option C  
                            Explanation:  
                                
                         
                     
                    
                    
                    
                    
                    
                    
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                | 215.  | 
The material which undergo recoverable deformation and exhibit rubber like elsticity are called |  
 
 
                
			 
				
					
				| A. | 
                 Pure elastic materials | 
				 				 B. | 
                 Elastomers | 
				  
				 
				 				 | C. | 
                 Rubbers | 
				 				 D. | 
                 Creep-elastic | 
				 				  
				 
				 				  
				    | E. | 
                    None of the above | 
					
					    | 
                   | 
				 
				  
				 				 
				  
                    
                        
                        
                            Answer: Option B  
                            Explanation:  
                                
                         
                     
                    
                    
                    
                    
                    
                    
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                | 216.  | 
The greatest amount of strain energy per unit volume that a material can absorb sithout exceeding its elastic limit is |  
 
 
                
			 
				
					
				| A. | 
                 Elastic limit | 
				 				 B. | 
                 Toughness | 
				  
				 
				 				 | C. | 
                 Resilience | 
				 				 D. | 
                 Proof resilience | 
				 				  
				 
				 				  
				    | E. | 
                    Endurance limit | 
					
					    | 
                   | 
				 
				  
				 				 
				  
                    
                        
                        
                            Answer: Option B  
                            Explanation:  
                                
                         
                     
                    
                    
                    
                    
                    
                    
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                | 217.  | 
Machinability of a metal depends on |  
 
 
                
			 
				
					
				| A. | 
                 Tensile strength | 
				 				 B. | 
                 Hardness | 
				  
				 
				 				 | C. | 
                 Toughness | 
				 				 D. | 
                 (A) and (B) above | 
				 				  
				 
				 				  
				    | E. | 
                    (B) and (C) above | 
					
					    | 
                   | 
				 
				  
				 				 
				  
                    
                        
                        
                            Answer: Option D  
                            Explanation:  
                                
                         
                     
                    
                    
                    
                    
                    
                    
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                | 218.  | 
The variable stress below which the probability of failure of a material is negligible, is called |  
 
 
                
			 
				
					
				| A. | 
                 Elastic limit | 
				 				 B. | 
                 Plastic limit | 
				  
				 
				 				 | C. | 
                 Yield point | 
				 				 D. | 
                 Endurance limit | 
				 				  
				 
				 				  
				    | E. | 
                    Tolerance limit | 
					
					    | 
                   | 
				 
				  
				 				 
				  
                    
                        
                        
                            Answer: Option E  
                            Explanation:  
                                
                         
                     
                    
                    
                    
                    
                    
                    
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                | 219.  | 
The modulus of elasticity E, the modulus of rigidity C, and Poisson's ratio are related by the equation |  
 
 
                
			 
				
					
				| A. | 
                 E = 2G (1 +  | 
				 				 B. | 
                 E = G (2 +  | 
				  
				 
				 				 | C. | 
                 E = G (1+ 2 | 
				 				 D. | 
                 E = 2G (1 -  | 
				 				  
				 
				 				  
				    | E. | 
                    E = 2G (1 - 2 | 
					
					    | 
                   | 
				 
				  
				 				 
				  
                    
                        
                        
                            Answer: Option A  
                            Explanation:  
                                
                         
                     
                    
                    
                    
                    
                    
                    
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                | 220.  | 
The modulus of elasticity E, the bulk modulus of elasticity K and the Poisson's ratio are related by the relation |  
 
 
                
			 
				
					
				| A. | 
                 E = K (1 -  | 
				 				 B. | 
                 E = 2K (1 +  | 
				  
				 
				 				 | C. | 
                 E = K (2 +  | 
				 				 D. | 
                 E = 3K (1 - 2 | 
				 				  
				 
				 				  
				    | E. | 
                    K = (1 +  | 
					
					    | 
                   | 
				 
				  
				 				 
				  
                    
                        
                        
                            Answer: Option D  
                            Explanation:  
                                
                         
                     
                    
                    
                    
                    
                    
                    
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