Hindustan Petroleum Corporation Limited Placement Paper Contributed by Rajiv updated on Mar 2019

                          HPCL Model Test Paper – Electrical & Electronics Engineering 

Complete the following statement:

1. Space charge region around a p – n junction
a. Contains one type of mobile carriers depending on the level of doping of the p or n regions
b. Does not contain mobile barriers
c. Contains electrons only as free carriers
d. Contains both free electrons and holes

2. What will be the consequences, if you remove the bypass capacitor across the emitter – leg resistor in a CE amplifier?
a. Decrease in voltage gain
b. Increase in current gain
c. Increase in voltage gain
d. Decrease in current gain

4. On what does the frequency of the ripple in the output voltage of a 3 – phase semi - converter depends upon?
a. Firing angle and supply frequency
b. Firing angle and load resistance
c. Only on load circuit parameters
d. Firing angle and load inductance

5. Which oscillator comprises of the highly stable resonance characteristic?
a. Colpitts
b. Hartley
c. Weinbridge
d. Crystal

6. ISDN handles data pertaining to
a. Computer data only
b. All digital services
c. Speech only
d. Speech and video

7. Which converter can operate in both 3 and 6 pulse modes?
a. 3 phase full converter
b. 1 phase full converter
c. 3 phase half wave converter
d. 3 phase semi – converter

8. When do you use analog data acquisition system?
a. Narrow bandwidth and high accuracy are required
b. Wide bandwidth and low accuracy are required/sufficient
c. Wide bandwidth and high accuracy are required
d. Narrow bandwidth and low accuracy are required/ sufficient

9. With which of the option can you carry out the measurement of frequency?
a. Wien’s bridge
b. Owen’s bridge
c. Schering’s bridge
d. Maxwell’s inductance – capacitance bridge

10. What will be the minimum number of line currents when the total number of branches in a network is = b and the graph of the network has ‘n’ number of branches?
a. b – n
b. n
c. b
d. b + n

11. The equation of continuity defines the relation between:
a. flux density and charge density
b. electric field and magnetic field
c. current density and charge density
d. electric field and charge density

12. The E and H vector fields in a travelling electromagnetic wave are:
a. Parallel in space
b. Perpendicular in space
c. H is in the direction of wave travel
d. E is in the direction of wave travel

13. What will be the dominant cut off wavelength if for a rectangular wave guide 2.5cm * 1.2cm?
a. 2.4 cm
b. 5 cm
c. 3.7 cm
d. 2.5 cm

14. The device used for providing rate feedback in position control systems is called:
a. Synchro
b. Servomotor
c. Potentiometer
d. Tachogenerator

15. What will you use to eliminate Harmonics?
a. Short pitch winding
b. Skewing of rotor
c. Distribution winding
d. All of the above

16. What is the temperature of electrode in Arc furnace?
a. 1500 degree
b. 4500 degree
c. 1000 degree
d. 1500 to 3500 degree

17. Which of the element retains its energy after its source is disconnected?
a. Capacitor
b. Resister
c. Thermistor
d. Inductor

18. What does a sine wave generates when given as an input to Schmitt trigger?
a. Saw tooth wave
b. Sine wave
c. Square wave
d. Triangle wave

19. What does Hays Bridge and Schering Bridge used to measure?
a. Capacitance, Inductance
b. Inductance, Inductance
c. Resistance, Capacitance
d. Inductance, Capacitance

20. What will be the power factor if the two watts meters measurement’s reading ratio is –(1-sqrt3):(1+sqrt3)?
a. 0
b. 1
c. 0.866
d. 0.707

21. Choose which transistor mode gives the inverted output?
a. Common collector
b. Common base
c. Common emitter
d. None of the above

22. What are the elements in the circuit when V=100sin (1000t+46 deg), I=2Sin (1000t+80 deg)?
a. R=40 ohm, L=30mH
b. R=40 ohm, L=33.3 micro farads
c. R=30 ohm, C=33.3 micro farads
d. R=30 ohm, L=30mH

23. What is the function of a closed loop transfer when G(s) = (1-s)/s(s+2)?
a. Marginally stable
b. Stable
c. Unstable
d. All of the above

24. How can you improve the stability of transient?
a. Auto re-closers
b. By putting series capacitor
c. By using dynamic resister
d. All of the above

25. What material is generally used while making power diode?
a. Germanium
b. Silicon
c. Both
d. None of the above

26. In which mode will you find the diode when both the junction of NPN diode is reverse biased?
a. Cut-off
b. Inverted
c. Active
d. Saturation

27. Convert the 101101 Binary number into Octal number.
a. 51
b. 65
c. 45
d. 55

28. In which band does the free electron exist?
a. 2
b. 3
c. 1
d. Conduction band

29. What is the efficiency of half wave rectifier?
a. 50%
b. 100%
c. 45%
d. 86%

30. What will be the value of Acm when CMRR of an OP AMP is given as 80db and Ad is 20000?
a. 2
b. 8
c. 4
d. 1