Electronic & Electrical Fundamentals Flashcards
7 cards from real CBT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Electronic & Electrical Fundamentals flashcards as text
What is the impedance of a series RLC circuit at resonance?
Answer: Equal to the resistance only
At resonance, inductive and capacitive reactances cancel, leaving only the resistance as the circuit impedance.
A transformer has a primary winding of 500 turns and a secondary of 100 turns. If the primary voltage is 120V, what is the secondary voltage?
Answer: 24V
Using the turns ratio formula: Vs = Vp × (Ns/Np) = 120 × (100/500) = 24V.
Which semiconductor device is typically 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.
In a parallel RC circuit, what happens to total impedance as frequency increases?
Answer: Impedance decreases
As frequency rises, capacitive reactance decreases, reducing the overall parallel impedance of the RC circuit.
What is the primary function of a bypass capacitor in an amplifier circuit?
Answer: Block DC while passing AC signals to ground
A bypass capacitor shorts AC signals to ground at a specific frequency, effectively removing the emitter resistor from the AC signal path to increase gain.
Which law states that the algebraic sum of currents at any node in a circuit equals zero?
Answer: Kirchhoff's Current Law
Kirchhoff's Current Law (KCL) states that the sum of currents entering a node equals the sum of currents leaving it.
What type of filter passes frequencies below a cutoff frequency and attenuates those above it?
Answer: Low-pass filter
A low-pass filter allows signals with frequencies lower than the cutoff frequency to pass while attenuating higher frequencies.