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Practice

Components & Circuits — Practice

The parts a station is built from — passives, semiconductors, power supplies and amplifier stages. Untimed topic practice with a full explanation after every question, so a wrong answer becomes a study note rather than a dead end.

Questions

12

Time limit

Untimed

Pass mark

60%

Before you start

  • Untimed. The explanation appears as soon as you answer, because the point here is to learn rather than to score.
  • Mark an answer as a guess and it enters your review queue even if it happened to be right.
  • Every answer moves your ability estimate for that topic and updates your readiness score.
  • Retake as often as you like.

Sample questions

A resistor is marked brown-black-red. What is its nominal value?

  • 100 Ω
  • 1,000 Ω
  • 10,000 Ω
  • 12 Ω

Why 1,000 Ω is right: Brown = 1, black = 0, and red as the multiplier means ×100. So 10 × 100 = 1,000 Ω, or 1 kΩ.

A gold tolerance band on a resistor indicates a tolerance of:

  • ±1%
  • ±2%
  • ±5%
  • ±10%

Why ±5% is right: Gold indicates ±5% and silver indicates ±10%. Brown and red bands are used for the tighter ±1% and ±2% grades.

What happens to the reactance of a capacitor as the applied frequency increases?

  • It increases
  • It decreases
  • It stays constant
  • It becomes purely resistive

Why It decreases is right: Capacitive reactance is Xc = 1 ÷ (2πfC), so it falls as frequency rises. A capacitor blocks DC but passes high-frequency AC readily.