Basic Electronics Quiz

07/28/2001

Meters

  1. A 20 micro-amp meter movement, with an internal resistance (Rm) of 172 ohms, is considered to have a "sensitivity" of _________ ohms per volt.
  2. A 50 micro-amp meter movement, with an internal resistance (Rm) of 212 ohms will read _________ v when reading full scale.
  3. A 40K ohms per volt meter sensitivity means that the meter will read full scale at what current through the meter? _________ .
  4. A voltmeter constructed from a 250 micro-amp movement, will require a total resistance of _________ ohms, to read 60V as a full scale reading.
  5. A voltmeter constructed from a 100 micro-amp movement, that has a total resistance of 145K ohms, will require _________ V to read full-scale.

Inductance and Capacitance

  1. A 55 micro-henry coil in series with a 12 mhy coil, both of which are in parallel with a 118 micro-henry coil, would result in a total inductance of _________ hy.
  2. A 300pf capacitor oin series with a 12pf capacitor would be _________ pf total.
  3. The Capacitive Reactance of a 150pf capacitor at 455Khz would be _________ ohms.
  4. The Inductive Reactance of a 410mhy inductor at 814 Hz would be _________ ohms.
  5. With L1=14mhy, and L2=27mhy, compute both the series and parallel inductance as totals:
    Lt(series) = _________ mhy
    Lt(parallel) = _________ mhy
  6. With C1=33pf, and C2=4.7pf, compute both the series and parallel capacitance as totals:
    Ct(series) = _________ pf
    Ct(parallel) = _________ pf

Time Constants

  1. A series circuit of a 45mhy inductance, and a 680 ohm resistance, connected across a 12V source would:
    • show a CEMF of 6.8V across the inductor at 1.1 Time Constants.
    • reach 11.4 ma after 85 microseconds.
    • to a CEMF of 63.2% of the 12V in 22 microseconds.
    • reach 35% of I(max) in 1.05 Time Constants.

Resonance

  1. A 150pf capacitor inseries with a 410 mhy inductor will be resonant at _________ Hz.
  2. A series inductance of 80 micro-henry, and a capacitance of 100pf, would:
    • resonate at 1.55Mhz.
    • have both XL and XC = 895 ohms at resonance.
    • appear as a capacitance at 2.05 Mhz.
    • show more voltage across the capacitor than the inductor at 4.77 Mhz.

Conversions

Fill in all the missing values in the chart below:

RMS P-P Ave Peak
115V
1800V
440V
75V

Properties

  1. Resistivity is:
    • opposition to change in current flow.
    • total opposition to current flow.
    • property of a substance that opposes current flow.
    • property that resists an Electrostatic Field.
  2. Reactance is:
    • the property that reacts to a Magnetic Field.
    • total opposition to Electrostaic-Flux.
    • opposition to change in current or voltage.
    • opposition to magnetic current flow.
  3. Reluctance is:
    • the property that impedes flux of any kind.
    • the total opposition to Electrostatic Flux.
    • the amount of opposition to change in flux.
    • the total opposition to Magnetic Flux.
  4. Permeability is:
    • the Specific Permeance of a particular substance, compared with that of a vacuum.
    • the ease by which an Electrostatic Field may be set up within a substance.
    • the number of lines of flux per sq. cm.