Electromagnetic Interfernce and Electromagnetic Compatibility Mid - I, September - 2014

1.__________ is needed for EMI/EMC testing, because of the dirty conditions outside the test cell, and the potential for particulates to rain off the overhead anechoic foam
  • Dust Tent
  • Auxiliary cooling
  • Emission Testing
  • both A & B
Answer: A
2.The velocity field is commonly referred to as _________ because it stores and transports energy in the near area of its source.
  • near field
  • reactive field
  • storage field
  • all the above
Answer: D
3._________ and ______ generate the conducted emission and then the radiated emission.
  • Current peaks
  • voltage drops
  • Inductance
  • both A & B
Answer: D
4.Conducted noise is coupled between components through interconnecting wires such as through _________
  • power supply
  • ground wires
  • both A & B
  • None
Answer: C
5._________ occurs when source and victim are separated by a large distance, typically more than a wavelength.
  • Radiative coupling
  • electromagnetic coupling
  • both A & B
  • inductive coupling
Answer: C
6.Electric field coupling is caused by a voltage difference between conductors. The coupling mechanism may be modeled by
  • a capacitor
  • a transformer
  • a resistor
  • an inductor
Answer: A
7.The EMI source minus the coupling mechanism path losses should result in an emission level that is _________ the victim's susceptibility threshold minus a predetermined safety margin.
  • equal
  • greater than
  • less than
  • not equal
Answer: C
8.Conducted emissions and susceptibility tests with ________ and _______ do not require radiators, but do require good access to connectors
  • SIU
  • PDU
  • both A & B
  • EMI
Answer: C
9._________ occurs when a varying magnetic field exists between two parallel conductors typically less than a wavelength apart, inducing a change in voltage along the receiving conductor.
  • Inductive coupling
  • magnetic coupling
  • both A & B
  • none
Answer: C
10.The aim of an equipotential bonding network is to improve the _________ performance.
  • EMC
  • EMI
  • EMD
  • both A & B
Answer: A
11.____________ is capable of providing clean, dry environment before/during/after EMI/EMC testing
Answer: Dust Tent
12.__________________ is said to exist when undesirable voltages or currents are present to influence adversely the performance of a device
Answer: Electromagnetic Interference
13._____________ is the mechanisms by which EMI is able to travel from source to victim.
Answer: Coupling
14.Inductive coupling is namely capacitive coupling and ______________ induction.
Answer: Magnetic
15.Lightning induces electromagnetic emissions which propagate over distances ranging up to several thousand kilometers, causing ____________ in the electromagnetic spectrum.
Answer: Spikes or sharp random pulses
16.The boundary between the ______________ and the ________________ is generally considered to lie around 2D2/λ, where D is the size of the transmitting antenna.
Answer: Near field, far field
17.The voltages and currents on a multi-conductor transmission line, within the approximations of standard transmission line theory, are governed by ________________
Answer: Coupled partial differential equations.
18.The interference is produced by a source emitter and is detected by a susceptible victim via a _________________
Answer: Coupling path
19.________________is a measure of how well an enclosure attenuates electromagnetic fields
Answer: Shielding effectiveness
20._______________ Coupling is caused by current flow in conductors. The coupling mechanism may be modeled by a transformer.
Answer: Magnetic field