E5E Skin effect; electrostatic and
electromagnetic fields
E5E01
(A)
What is
the result of skin effect?
A. As frequency increases,
RF current flows in a thinner layer of the conductor, closer to the surface
B. As frequency decreases, RF current flows in
a thinner layer of the conductor, closer to the surface
C. Thermal effects on the surface of the
conductor increase the impedance
D. Thermal effects on the surface of the
conductor decrease the impedance
E5E02
(C)
What
effect causes most of an RF current to flow along the surface of a conductor?
A. Layer effect
B. Seeburg effect
C. Skin effect
D. Resonance effect
E5E03
(A)
Where
does almost all RF current flow in a conductor?
A. Along the surface of the
conductor
B. In the center of the conductor
C. In a magnetic field around the conductor
D. In a magnetic field in the center of the
conductor
E5E04
(D)
Why
does most of an RF current flow within a few thousandths of an inch of its
conductor's surface?
A. Because a conductor has AC resistance due to
self-inductance
B. Because the RF resistance of a conductor is
much less than the DC resistance
C. Because of the heating of the conductor's
interior
D. Because of skin effect
E5E05
(C)
Why is
the resistance of a conductor different for RF currents than for direct
currents?
A. Because the insulation conducts current at
high frequencies
B. Because of the Heisenburg Effect
C. Because of skin effect
D. Because conductors are non-linear devices
E5E06
(C)
What
device is used to store electrical energy in an electrostatic field?
A. A battery
B. A transformer
C. A capacitor
D. An inductor
E5E07
(B)
What
unit measures electrical energy stored in an electrostatic field?
A. Coulomb
B. Joule
C. Watt
D. Volt
E5E08
(B)
What is
a magnetic field?
A. Current through the space around a permanent
magnet
B. The space around a
conductor, through which a magnetic force acts
C. The space between the plates of a charged
capacitor, through which a magnetic force acts
D. The force that drives current through a
resistor
E5E09
(D)
In what
direction is the magnetic field oriented about a conductor in relation to the
direction of electron flow?
A. In the same direction as the current
B. In a direction opposite to the current
C. In all directions; omnidirectional
D. In a direction determined
by the left-hand rule
E5E10
(D)
What
determines the strength of a magnetic field around a conductor?
A. The resistance divided by the current
B. The ratio of the current to the resistance
C. The diameter of the conductor
D. The amount of current
E5E11
(B)
What is
the term for energy that is stored in an electromagnetic or electrostatic
field?
A. Amperes-joules
B. Potential energy
C. Joules-coulombs
D. Kinetic energy