Model question by NEC and solution

All questions are from NEC model question for Electrical Engineering Licence. You can test all questions yourself.

Multiple Choice
15x1=15 Marks

1. What will be the rated speed for 8 pole 50 Hz synchronous generator?
A. 800 rpm
B. 600 rpm
C. 750 rpm
D. 1000 rpm
2. EMF induced in a coil rotating in a uniform magnetic field will be maximum when the;
A. Rate of cutting flux by the coil sides is minimum
B. Flux linking with the coil is maximum
C. Rate of change of flux linkage is minimum
D. Rate of change of flux linkage is maximum
3. In a transformer, electrical power is transferred from primary to secondary;
A. Through air
B. By magnetic flux
C. Through insulating medium
D. None of the above
4. The stator core of a 3-phase induction motor is laminated in order to reduce the:
A. Eddy current loss
B. Hysteresis loss
C. Both A and B
D. None of the above
5. Single line diagram of which of the following power system is possible?
A. Power system with LG fault
B. Balanced power system
C. Power system with LL fault
D. Power system with LLG fault
6. What is the full from of SCADA?
A. Supervisory Control and Document Acquisition
B. Supervisory Control and Data Acquisition
C. Supervisory Column and Data Assessment
D. Supervisory Column and Data Analysis
7. Which of the following connections are perfect for electrical instrumentation?
A. Opened CT and Opened PT
B. Closed CT and Closed PT
C. Opened CT and Closed PT
D. Closed CT and Opened PT
8. The burden of protective current transformer is specified in;
A. Percentage of load current
B. Percentage of ratio error
C. Volt-Ampere
D. Percentage of phase error
9. The electrolyte used in Li-ion battery is;
A. Lead peroxide
B. Lithium-based gel
C. Sulfur dioxide
D. Cobalt
10. A lightning arrester provides;
A. High impedance path
B. Low resistance path
C. Low impedance path
D. None of the above
11. The short circuit test of a transformer gives the information of
A. Cu losses
B. core losses
C. winding circuit impedance
D. none
12. The fault clearing time of a circuit breaker is usually
A. few minutes
B. few seconds
C. one second
D. few cycles of supply voltage
13. A PT is connected in ...... with the line.
A. series
B. Parallel
C. Both
D. None
14. A relay used on very long transmission lines is
A. mho's relay
B. reactance relay
C. impedance relay
D. none
15. A thyristor (SCR) is a
A. P-N-P device
B. N-P-N device
C. P-N-P-N device
D. P-N device