Extra-Study/pages/E6D.md

E6D Inductors and piezoelectricity: permeability, core material and configuration; transformers; piezoelectric devices

• E6D01 (C) What is piezoelectricity? #card
  • A. The ability of materials to generate electromagnetic waves of a certain frequency when voltage is applied
  • B. A characteristic of materials that have an index of refraction which depends on the polarization of the electromagnetic wave passing through it
  • C. A characteristic of materials that generate a voltage when stressed and that flex when a voltage is applied
  • D. The ability of materials to generate voltage when an electromagnetic wave of a certain frequency is applied
• E6D02 (A) What is the equivalent circuit of a quartz crystal? #card
  • A. Series RLC in parallel with a shunt C representing electrode and stray capacitance
  • B. Parallel RLC, where C is the parallel combination of resonance capacitance of the crystal and electrode and stray capacitance
  • C. Series RLC, where C is the parallel combination of resonance capacitance of the crystal and electrode and stray capacitance
  • D. Parallel RLC, where C is the series combination of resonance capacitance of the crystal and electrode and stray capacitance
• E6D03 (A) Which of the following is an aspect of the piezoelectric effect? #card
  • A. Mechanical deformation of material due to the application of a voltage
  • B. Mechanical deformation of material due to the application of a magnetic field
  • C. Generation of electrical energy in the presence of light
  • D. Increased conductivity in the presence of light
• E6D04 (B) Why are cores of inductors and transformers sometimes constructed of thin layers? #card
  • A. To simplify assembly during manufacturing
  • B. To reduce power loss from eddy currents in the core
  • C. To increase the cutoff frequency by reducing capacitance
  • D. To save cost by reducing the amount of magnetic material
• E6D05 (C) How do ferrite and powdered iron compare for use in an inductor core? #card
  • A. Ferrite cores generally have lower initial permeability
  • B. Ferrite cores generally have better temperature stability
  • C. Ferrite cores generally require fewer turns to produce a given inductance value
  • D. Ferrite cores are easier to use with surface-mount technology
• E6D06 (D) What core material property determines the inductance of an inductor? #card
  • A. Permittivity
  • B. Resistance
  • C. Reactivity
  • D. Permeability
• E6D07 (D) What is the current that flows in the primary winding of a transformer when there is no load on the secondary winding? #card
  • A. Stabilizing current
  • B. Direct current
  • C. Excitation current
  • D. Magnetizing current
• E6D08 (B) Which of the following materials has the highest temperature stability of its magnetic characteristics? #card
  • A. Brass
  • B. Powdered iron
  • C. Ferrite
  • D. Aluminum
• E6D09 (C) What devices are commonly used as VHF and UHF parasitic suppressors at the input and output terminals of a transistor HF amplifier? #card
  • A. Electrolytic capacitors
  • B. Butterworth filters
  • C. Ferrite beads
  • D. Steel-core toroids
• E6D10 (A) What is a primary advantage of using a toroidal core instead of a solenoidal core in an inductor? #card
  • A. Toroidal cores confine most of the magnetic field within the core material
  • B. Toroidal cores make it easier to couple the magnetic energy into other components
  • C. Toroidal cores exhibit greater hysteresis
  • D. Toroidal cores have lower Q characteristics
• E6D11 (B) Which type of core material decreases inductance when inserted into a coil? #card
  • A. Ceramic
  • B. Brass
  • C. Ferrite
  • D. Aluminum
• E6D12 (C) What causes inductor saturation? #card
  • A. Operation at too high a frequency
  • B. Selecting a core with low permeability
  • C. Operation at excessive magnetic flux
  • D. Selecting a core with excessive permittivity