Electrical Engineering Flashcards
6 cards from real BE/B Eng Bachelor of Engineering practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Electrical Engineering flashcards as text
Which logic gate produces a HIGH output only when all inputs are HIGH?
Answer: AND
The AND gate outputs HIGH (1) only when every input is HIGH (1); any LOW input produces a LOW output.
What is the purpose of a flyback diode in a DC motor circuit?
Answer: To protect against voltage spikes when the motor turns off
A flyback (freewheeling) diode clamps the voltage spike generated by the motor's inductance when current is suddenly interrupted, protecting circuit components.
In a three-phase power system, what is the phase difference between each phase voltage?
Answer: 120 degrees
In a balanced three-phase system, the three sinusoidal voltages are each displaced by 120 degrees from one another.
What does the bandwidth of an amplifier represent?
Answer: The range of frequencies over which gain is within 3 dB of its midband value
Bandwidth is defined as the frequency range between the lower and upper -3 dB (half-power) points of an amplifier's frequency response.
Which type of semiconductor device is commonly used as a voltage regulator in simple circuits?
Answer: Zener diode
A Zener diode maintains a nearly constant voltage across its terminals when reverse biased beyond its breakdown voltage, making it ideal for voltage regulation.
What is the function of a Phase-Locked Loop (PLL) in communication systems?
Answer: To synchronize an output signal's phase with a reference input signal
A PLL locks its output oscillator's phase and frequency to match a reference signal, used in clock recovery, frequency synthesis, and demodulation.