Electronic & Electrical Fundamentals Flashcards

In a common-emitter BJT amplifier, what is the phase relationship between input and output signals?

Answer: 180° phase shift

A common-emitter amplifier inverts the signal, producing a 180° phase shift between input and output.

What is the time constant of a circuit with a 10kΩ resistor and a 100μF capacitor?

Answer: 1 second

The RC time constant τ = R × C = 10,000Ω × 0.0001F = 1 second.

What does the term 'dBm' represent in RF and broadcast engineering?

Answer: Decibels relative to 1 milliwatt

dBm is a unit of power expressed in decibels relative to a reference of 1 milliwatt.

In a full-wave rectifier with a center-tapped transformer, how many diodes are required?

Answer: Two

A center-tapped full-wave rectifier uses two diodes, one for each half of the AC cycle from the center-tapped secondary.

What is the voltage gain of an op-amp inverting amplifier with a feedback resistor of 100kΩ and an input resistor of 10kΩ?

Answer: -10

The gain of an inverting op-amp amplifier is -Rf/Rin = -100kΩ/10kΩ = -10.

Which type of capacitor is commonly used in high-frequency RF circuits due to its low parasitic inductance?

Answer: Surface-mount ceramic chip capacitor

Surface-mount ceramic chip capacitors have extremely low parasitic inductance and are ideal for high-frequency RF bypass and decoupling applications.

What is the Q factor of an inductor primarily a measure of?

Answer: The ratio of energy stored to energy dissipated per cycle

Q factor (quality factor) measures the ratio of reactive power stored to real power dissipated, indicating how 'ideal' the inductor is.