Electrical Engineering is part of Engineering and holds 3,646 questions with answers, free to read and with no account needed.
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Answer: A. Short transmission lines
Short transmission lines have relatively short physical lengths and operate at lower electrical voltage levels. Under these limited conditions, the total charging current drawn by line capacitance is extremely small. The...
Answer: C. Both A. and (b)
Electrical power transmission and distribution utilize both overhead line and underground cable systems. Overhead systems use bare conductors suspended in air supported by utility poles and towers. Underground systems em...
Answer: C. high voltage winding
High-voltage transformer windings carry lower currents compared to low-voltage windings of equivalent power rating. Lower currents allow tap-changer switch contacts to be smaller and more manageable in mechanical design....
Answer: D. all of the above
Galvanized steel wire provides high tensile strength and corrosion resistance needed for power line hardware. It is routinely deployed as stay wire to mechanically support utility poles against high wind loads. It also s...
Answer: D. no insulation is required
Aluminum Conductor Steel Reinforced cables combine two distinct metallic materials to achieve specific engineering goals. Aluminum strands provide high electrical conductivity, while the central steel core provides high...
Answer: D. increase the tensile strength
Aluminum conductors incorporate a central steel core to provide high mechanical tensile strength. Pure aluminum lacks the necessary mechanical rigidity to span long distances between transmission towers. The steel core b...
Answer: B. there is no current in the line
Isolators lack arc-extinguishing chambers and are strictly designed to operate as off-load disconnect switches. Opening an isolator while current flows would draw a severe electrical arc, damaging equipment and endangeri...
Answer: D. secondary distribution
Secondary distribution networks commonly utilize a three-phase four-wire scheme to supply diverse customer loads. The fourth wire serves as a neutral conductor, enabling simultaneous delivery of single-phase power. This...
Answer: C. between 20 and 500
Transistor current gain beta represents the ratio of collector current to base current in bipolar transistors. Semiconductor manufacturing processes and physical silicon properties limit this practical amplification rati...
Answer: C. Decreases
Resonant frequency is inversely proportional to the square root of inductance multiplied by capacitance. Raising either inductance or capacitance increases the denominator in the resonance equation. An increased denomina...
Answer: E. All of the above
Interconnected power systems involve complex networks that can be solved using various established analytical methods. Thevenin's theorem, current superposition, and Kirchhoff's laws all serve as valid techniques for net...
Answer: B. electrical conductivity
Copper possesses a higher electrical conductivity than aluminum for the exact same cross-sectional area. This means aluminum requires a larger cross-section to carry the same electrical current load as copper. Despite lo...
Answer: B. generators
Synchronous generators require precise terminal voltage control as electrical load demands fluctuate throughout the day. Electro-mechanical voltage regulators automatically adjust generator field excitation currents to m...
Answer: D. Any of the above
Guard rings reduce capacitance imbalances across individual insulator discs in high voltage strings. Grading insulators ensures voltage distributes evenly across each unit from cross-arm to conductor. Longer cross-arms i...
Answer: D. less than 1
The common collector configuration, often called an emitter follower, replicates the input voltage at its output. Negative feedback inherent in this circuit design keeps the output voltage slightly below the input voltag...
