Electronics Flashcards
7 cards from real ASVAB practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Electronics flashcards as text
Which semiconductor device can be used to amplify a signal using three terminals: gate, source, and drain?
Answer: MOSFET
A MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) uses gate, source, and drain terminals and controls current via an electric field.
In a full-wave bridge rectifier, how many diodes are required?
Answer: 4
A bridge rectifier uses 4 diodes arranged in a bridge configuration to convert both half-cycles of AC into DC.
What does the term 'gain' mean in the context of an amplifier?
Answer: The ratio of output signal amplitude to input signal amplitude
Gain is the ratio of output to input (voltage, current, or power), indicating how much the amplifier increases the signal.
A fuse is rated at 5 amps. If the circuit draws 7 amps, what will happen?
Answer: The fuse will blow, opening the circuit
When current exceeds the fuse rating, the fuse element melts and opens the circuit, protecting the wiring and components.
What is the function of an oscilloscope in electronics testing?
Answer: To display voltage waveforms as a function of time
An oscilloscope displays voltage versus time on a screen, allowing technicians to visualize signal shape, frequency, and amplitude.
Which law states that the total current entering a junction equals the total current leaving the junction?
Answer: Kirchhoff's Current Law
Kirchhoff's Current Law (KCL) states that charge is conserved at any node, so all currents entering must equal all currents leaving.
What is the impedance of a pure inductor at DC (zero frequency)?
Answer: Zero (short circuit)
Inductive reactance XL = 2πfL; at DC (f=0), XL = 0, so an ideal inductor is a short circuit to DC.