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. current
A bipolar junction transistor operates by controlling a large collector current using a much smaller base current. The input control mechanism relies on current flow across the forward-biased base-emitter semiconductor j...
Answer: A. remain the same
Switching a transistor configuration alters external terminal connections and signal paths without changing internal DC bias points. External biasing resistors and power supplies establish fixed emitter, base, and collec...
Answer: B. Maximum
At the resonant frequency the impedance of a parallel tuned load reaches its absolute maximum. Maximum load impedance causes the transistor collector voltage swing to reach its highest level. Consequently the tuned ampli...
Answer: C. Current amplification
Parallel resonance produces large circulating currents within the internal tank circuit branches compared to the supply. The reactive currents flowing between the inductor and capacitor amplify internally while the line...
Answer: B. Capacitive
Capacitive reactance varies inversely with signal frequency, becoming larger at lower frequencies. When a series LC circuit operates below its resonant frequency, capacitive reactance exceeds inductive reactance. This do...
Answer: A. XL increases and XC decreases
Inductive reactance formula states that XL is directly proportional to operating frequency in an AC circuit. Capacitive reactance formula proves that XC is inversely proportional to frequency in any capacitor network. Th...
Answer: D. 20 kHz
Bandwidth of a tuned circuit is calculated by dividing resonant frequency by the Q factor. Dividing one thousand kilohertz by a Q factor of fifty yields twenty kilohertz. Therefore the calculated bandwidth for this speci...
Answer: C. 2pfrL / R
The quality factor Q represents the ratio of stored reactive energy to dissipated resistive energy per cycle. For a series LC circuit, this mathematical ratio translates directly to inductive reactance divided by resista...
Answer: C. 0o
At series resonance, the inductive reactance and capacitive reactance of the circuit are equal in magnitude. Because their reactances cancel each other out, the net reactive impedance of the series circuit becomes zero....
Answer: A. Voltage amplification
Series resonance produces very high voltages across the individual inductor and capacitor components within the circuit. These reactive component voltages can significantly exceed the input voltage supplied by the AC sou...
Answer: B. Is decreased
Quality factor measures the ratio of stored energy to dissipated energy within a tuned circuit. Raising the internal resistance increases power dissipation losses inside the inductor winding. Increased internal resistanc...
Answer: A. Loose
Loose coupling between double-tuned circuits minimizes the mutual inductance linking the two resonant stages together. Reducing this magnetic linkage prevents the resonance curve from broadening or splitting into twin pe...
Answer: B. Inductive
Inductive reactance increases directly with signal frequency according to the standard formula for inductors. When operating above the resonant frequency, inductive reactance exceeds capacitive reactance in a series LC c...
Answer: B. 1020 kHz , 980 kHz
Cutoff frequencies flank the center frequency symmetrically based on the established bandwidth of the tuned circuit. Calculating symmetrical offsets around a 1000 kHz center frequency yields upper and lower frequency bou...
Answer: B. Is increased
The quality factor of a parallel LC circuit is directly proportional to the square root of L over C. Increasing the inductance to capacitance ratio increases the stored magnetic energy relative to electric energy. This h...
