Download What does the “PASSIVE” device mean

AE1M13VES
16th. January 2014
first name:
surname:
1. What does the “PASSIVE” device mean?
 it can be just resistor, capacitor or inductor, no other devices,
 device, where output power (Pout) is lower (or equal) than the input power (Pin),
 device, where input power (Pin) is lower (or equal) than the output power (Pout),
 all the semiconductor devices, e.g. LED, thyristors etc.
2. What does the “LINEAR” device mean?
 device, that can be described by means of simple linear formulas and their
combinations,
 device, that can generate harmonic signals and their combinations (intermodulation),
 device, which behavior is determined by differential equations with both time and
coordinate variables,
 device that exhibits linear dependence between temperature and its resistivity.
3. Which elements (and their combinations) are not often used for common resistors:
 Gold (Au),
 Carbon (C),
 oxides of Pt + Ni,
 oxides of Fe + Cr + Ni.
4. In which units is given the temperature coefficient of resistivity (TCR)?
 -1
 K-1
 K/W
 J/kg
5. How can we define the dissipation factor (D)?
 it is an angle between current I flowing trough the capacitor and applied voltage V,
 it is an angle between voltage V on the capacitor and voltage on the parasitic
inductance L of the outlets,
 it is an parameter responsible for total power losses in the capacitor,
 it is a self resonance frequency; above this limit capacitor starts to be “more
inductance” than the capacitor.
6. Which important materials are used for electrolyte capacitors?
 Aluminum (Al) or Tantalum (Ta), solution of KOH or H2SO4,
 Stainless steel (Fe), other ferromagnetic metals (Ni, Cr, Etc.),
 Carbon (C),
 Silicon-carbide (SiC).
7. Electrolyte capacitors are typically used:
 for high voltage and high frequency applications (low power losses needed),
 as charge accumulators thanks to big specific capacity,
 as variable capacitors for tuned RF applications,
 for filtering in AC/DC converters, in power sources.
AE1M13VES
16th. January 2014
first name:
surname:
8. Variable capacitors are typically made and designed as:
 rotating parts with an air (dielectric) gap,
 foil capacitors based on plastic dielectric (PE, PA, PVC, etc.),
 rolled capacitors with metallization on both electrodes,
 ceramic capacitors made from ferroelectric (FexOy) or similar dielectric with large
permittivity.
9. Inductors, coils and transformers can be made:
 as a simple air-winding - without any magnetic circuit,
 only from ferromagnetic cores (Fe, Ni, Cr),
 only from dia/paramagnetic cores (Al, Mn, Cu),
 from a copper winding wounded on some ferromagnetic core.
10. Quality factor (Q) of inductor can be defined as:
 ratio between imaginary and real part of the inductor’s impedance,
 an angle between flowing current in inductor and voltage on the inductor’s outlets,
 an product of absolute and relative permeability of used ferrite material,
 maximum magnetic flux in the middle of the magnetic core.