Practice Test GeeksOAR Test Practice Test
← All OAR Flashcard Decks

OAR Mechanical Comprehension: Electricity Flashcards

7 cards from real OAR practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 OAR Mechanical Comprehension: Electricity flashcards as text

  1. In a series circuit with a 12V source and three equal 4Ω resistors, what is the voltage drop across each resistor?

    Answer: 4V

    Total resistance is 12Ω, current is 1A, and voltage drop across each 4Ω resistor is 1A × 4Ω = 4V.

  2. What is the purpose of a fuse in an electrical circuit?

    Answer: Protect against excessive current

    A fuse contains a wire that melts and breaks the circuit when current exceeds a safe level, preventing damage.

  3. Two identical 10Ω resistors are connected in parallel. What is the combined resistance?

    Answer: 5Ω

    Two identical resistors in parallel produce half the resistance of one: 10/2 = 5Ω.

  4. What unit measures electrical charge?

    Answer: Coulomb

    The coulomb (C) is the SI unit of electric charge; one ampere equals one coulomb per second.

  5. A transformer has 200 primary turns and 50 secondary turns. If the primary voltage is 120V, what is the secondary voltage?

    Answer: 30V

    Voltage ratio equals turns ratio: V_s = 120 × (50/200) = 120 × 0.25 = 30V.

  6. What type of electricity is produced by a battery?

    Answer: Direct current (DC)

    Batteries produce direct current (DC) because current flows consistently in one direction due to chemical reactions.

  7. Which component opposes changes in current in an AC circuit?

    Answer: Inductor

    An inductor stores energy in a magnetic field and opposes changes in current through electromagnetic induction.