EE DIAG PROF 1 - the branch of science concerned with the bodily structure of humans, animals, PDF

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the branch of science concerned with the bodily structure of humans, animals, and other living organisms, especially as revealed by dissectio...

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ELECTRICAL ENGINEERING REVIEW SERIES APRIL 2022 DIAGNOSTICS: REE PROFESSIONAL 1 1. Two wires A and B of the same material and length L and 2L have radius r and 2r respectively. The ratio of their specific resistance will be (a) 1 : 1 (b) 1 : 2 (c) 1 : 4 (d) 1 : 8 2. A network contains linear resistors and ideal voltage sources. If values of all the resistors are doubled then the voltage across each resistor is (a) halved (b) doubled (c) four times (d) not changed 3. Two incandescent light bulbs of 40 W and 60 W rating are connected in series across the mains. Then (a) the bulbs together consume 100 W (b) the bulbs together consume 50 W (c) the 60 W bulb glows brighter (d) the 40 W bulb glows brighter 4. Find the value of current flowing through the 5 ohm resistor: (a) 0.571 A (b) 0.033 A

(c) 0.071 A (d) 0.500 A

5. A 60 MW-Palimpinon of Dauin City power station has an annual peak load of 50 MW. The power station supplies loads having maximum demands of 20 MW, 17 MW, 10 MW and 9 MW. The annual load factor is 0.45. Find the diversity factor: (a) 1.43 (b) 1.12 (c) 1.08 (d) 1.19 6. A power station has to supply load as follows : Time (hours) : 0–6 6–12 12–14 14–18 Load (MW) : 45 135 90 150 The load factor is most nearly: (a) 0.641 (b) 0.373

18–24 75

(c) 0.494

(d)

0.822

7. A turbine in Agus IV Hydroelectric Plant operates under a head of 67 meters at a flowrate of 0.393 m3/s. If the turbine and generator efficiencies are 0.87 and 0.94, respectively. The kilowatts produced is most nearly: (a) 362 (b) 105 (c) 211 (d) 89 8. The Wind Power Project in Caraga Region, Mindanao will operate under an average wind speed of 90 kph. If the turbine available is 30 meters in diameter and 35% efficient, what power is generated using 25 turbines? Assume air density = 1.2 kg/m3 (a) 41 MW (b) 58 MW (c) 23 MW (d) 89 MW

9. A generating station has a maximum demand of 20 MW, a load factor of 0.6, a plant capacity of 0.48 and a plant use factor of 0.80. Find the reserve capacity of the plant: (a) 5000 kW (c) 3000 kW (c) 2000 kW (d) 1000 kW 10. Find the equivalent resistance between terminals A and B: (a) 3R/7 (c) 4R/7 (b) 8R/7 (d) 2R/7

11. The example of non-ohmic resistance is (a) copper wire (c) aluminium

(c) tungsten wire

(d)

gold wire

12. The electric current is due to the flow of (a) positive charges only (c) negative charges only (b) both positive and negative charges (d) magnetic field lines. 13. Eureka has ____________ temperature co-efficient of resistance. (a) almost zero (b) negative (c) positive

(d) none of the above

14. An electric fan and a heater are marked 100 Watt, 220 V and 1000 Watt, 220 V respectively. (a) The resistance of the heater is (c) greater than that of fan (b) less than that of fan (d) equal to that of fan 15. The figure shown represents a part of a closed circuit. The potential difference between A and B is: (a) 24 V (c) 0 V (b) 18 V (d) 6 V

16. The capacitance of a capacitor is __________ relative permittivity. (a) directly proportional to (c) inversely proportional to (b) independent of (d) directly proportional to square of 17. A capacitor opposes (a) change in current (b) both change in current and voltage

(c) change in voltage (d) none of the above

18. A parallel-plate air capacitor is immersed in oil of dielectric constant 2. The electric field between the plates is (a) increased 2 times (c) increased 4 times (b) decreased 2 times (d) none of above 19. Two capacitors have capacitances 25 µF when in parallel and 6 µF when in series. Their individual capacitances are (a) 12 µF and 13 µF (c) 15 µF and 10 µF (b) 10 µF and 8 µF (d) none of above 20. A flux density of 1.2 Wb/m2 is required in 2-mm air gap of an electromagnet having an iron path 1 m long. Calculate the current required if the electromagnet has 1,273 turns. Assume relative permeability of iron to be 1,500. (a) 1 A (b) 2 A (c) 3 A (d) 4 A 21. Which of the following does not change when a glass slab is introduced between the plates of a charged parallel plate capacitor? (a) electric charge (c) electric energy (b) capacitance (d) electric field intensity 22. A 16 µF capacitor is charged to 100 V. After being disconnected, it is immediately connected in parallel with an uncharged capacitor of capacitance 4µF. Determine the potential difference across the combination: (a) 90 V (b) 40 V (c) 60 V (d) 80 V 23. An another unit of inductance is: (a) Wb T/A (b) V-s/A

(c) H-turns2

(d) All three are equivalent

24. A parallel-plate capacitor has plates 0.1 mm apart, a plate area of 1 × 10^5 mm2, and a dielectric with a relative permittivity of 5. What is the voltage between the plates, if the capacitor has a charge of 5 uC? (a) 112.94 V (b) 183.23 V (c) 23.74 V (d) 75.53 V 25. Hysteresis loss in a magnetic material depends upon (a) area of hysteresis loop (c) frequency of reversed of field (b) volume of magnetic material (d) All the above 26. The (a) (b) (c) (b)

magnetic strength of an electromagnet can be increased by increasing current in the solenoid increasing the number of turns of the solenoid Both (a) and (b) None of above

27. If two series (a) L1 (c) L1

coils having self-inductances L1 and L2 and a mutual inductance M are connected in with opposite polarity, then the total inductance of the combination will be + L2 + 2M (b) L1 − L2 − 2M − L2 + 2M (d) L1 + L2 − 2M

28. A coil of 0.02 mH is carrying a current of 1 A. If this current is reversed in 0.02 s, the induced emf in the coil will be (a) 0.08 V (b) 0.004 V (c) 0.002 V (d) 0.02 V...