Important Question Electrical Engineer

1. The current through an inductance follows :
(1) A linear growth       
(2) A linear decay
(3) An exponential decay 
(4) An exponential growth              
Ans  (4)
2. Selectivity's of different resonance circuits are compared in terms of their :
(1) Impedances 
(2) Reactance 
(3) Frequencies    
(4) Band widths            
Ans  (4)
3. The dynamic impedance of an R-L and C parallel circuit at resonance is
(1)  R/LC       
(2) C/LR
(3) LC/R       
(4) L/CR               
Ans (4)
4. Inductive reactance is defined as the opposition offered by the........ of a circuit to the flow of an alternating sinusoidal current.
(1)Resistance      
(2) Inductance
(3)Capacitance    
(4) Voltage              
Ans  (2)
5. A power system is providing 250V A.C at 20 A. If the phase angle between current and voltage is 25° than what is the truelongest power used by the system.
(1) 2113.8 W          
(2) 4531.5 W
(3) 5517.2W         
(4) 11831.6 W           
Ans  (2)
6. To calculate the power factor which of the following is odd one :
(1) True power
(2) P/VI
(3) R/Z        
(4) V/I                
Ans  (4)
7. Unit of reactive power is :
(1) Watt        
(2) Kiol watt 
(3) VAR          
(4) Volt ampere              
Ans (3)
8. When XL is equal to XC :
(1)  Z = R        
(2) Z = XC
(3) Z = XL          
(4) None of these            
Ans (1)
9. At resonance , inductive reactance is equal :
(1) Resistance        
(2) Capacitance
(3) Capacitive Reactance        
(4)  Inductance             
Ans (3)
10. Three identical impedance are connected in delta to 3 phase supply of 400 V. The line current is 34.65 A and the total power taken is 14.4 kW. What is the resistance of the load in each phase ?
(1) 20         
(2) 16
(3) 12          
(4) 10             
Ans  (3)