Question Paper Electrical Engineering

1. The earthing electrodes should be placed within what distance in meters from the building whose installation system is being earthed
(1) 4     
(2) 2.5
(3) 1.5.   
(4) 0.5.         
Ans  (3)
2. Which insulation is most widely used for covering wires/cables used in internal wiring ?
(1)Paper     
(2) Wood 
(3) Glass       
(4) PVC             
Ans (4)
3. The efficiency normally obtained in circuit under the conditions of maximum power transfer is :
(1) 50%       
(2) 75%
(3) 100%      
(4) 25%             
Ans  (1)
4.  With the increases in the cross sectional area of the conductor, the value of resistane :
(1) Increase
(2)Remain same  
(3) Decrease       
(4) None of these     
Ans (3)
5. The earth's potential is taken as -
(1) infinite       
(2) supply voltage 
(3) 1 volt         
(4) Zero         
Ans  (4)
6. What is the maximum number of point of light, fan and socket - outlets that can be connected in one sub - circuit ?
(1)Twelve       
(2) Ten
(3)Four         
(4) Six         
Ans  (2)
7. Humans are more vulnerable to electric shock current at ?
(1) 50 Hz       
(3) 48 Hz
(3) 40 Hz      
(4) 45 Hz.            
Ans  (1)
8. For cleat wiring and 250 volts supply, the cables will be placed _____ a part centre to centre for single corw cables.
(1) 4.5 cm      
(2) 2.5 cm
(3) 3 cm         
(4) 4 cm .      
Ans (2)
9. For painful shock, what is the range of electric shock current at 50 Hz ?
 (1) 3-5 mA      
(2) 5-10 mA
(3) 0-3 mA        
(4) 0-1 mA.            
Ans  (2)
10. Minimum distance of underground cable from the foundation of building should be
(1) 100 cm             
(2) 50 cm  
(3)  10 cm         
(4) 5 cm.               
Ans  (3)