← All BEE Flashcard Decks

Measurement and Instrumentation Flashcards

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

Read the first 7 Measurement and Instrumentation flashcards as text
  1. Which bridge circuit is most commonly used to measure inductance?

    Answer: Maxwell bridge

    The Maxwell bridge balances inductance against a known capacitance and resistance to measure unknown inductance values.

  2. A current transformer (CT) should never be operated with its secondary:

    Answer: Open-circuited

    An open-circuited CT secondary causes dangerously high voltages due to the high magnetizing current in the primary.

  3. The sensitivity of a voltmeter is expressed in:

    Answer: Ohms per volt

    Voltmeter sensitivity (Ω/V) indicates how much resistance the meter presents per volt of full-scale deflection; higher is better.

  4. In a CRO, the time base is generated by:

    Answer: A sawtooth wave generator

    The sawtooth (ramp) wave sweeps the electron beam linearly across the screen at a controlled rate to create the time axis.

  5. Which error results from the loading effect of a voltmeter on a circuit?

    Answer: Systematic error

    Loading error is a systematic error because it consistently affects every measurement in the same direction due to the meter's finite input impedance.

  6. A megohmmeter (megger) is used primarily to measure:

    Answer: Insulation resistance of cables and equipment

    A megger applies a high DC voltage (typically 500–5000 V) to measure insulation resistance values in the megaohm range.

  7. The Lissajous figure on a CRO shows a straight line at 45°. What is the phase difference between the two signals?

    Answer: 0° or 180°

    A straight-line Lissajous figure indicates 0° (same phase) or 180° (opposite phase) between the two input signals.