A half-wave dipole is strung parallel to the ground. What is the polarization of its signal?
Vertical
Circular
Horizontal
Elliptical
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C. Horizontal
Polarization follows the orientation of the radiating element's electric field, so a horizontal wire radiates a horizontally polarized wave. Turning the same dipole upright would make it vertical.
Reference: Antenna fundamentals: polarization
What are the two leads of a semiconductor diode called, and how is one of them often marked?
Anode and cathode; a stripe marks the anode
Anode and cathode; a stripe marks the cathode
Emitter and collector; a dot marks the emitter
Source and drain; a tab marks the source
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B. Anode and cathode; a stripe marks the cathode
A diode has an anode and a cathode, and the band printed on the body identifies the cathode end. Emitter, collector, source and drain are transistor terminals.
Reference: Electronic components: diodes
The henry is the unit of which electrical property?
Inductance
Capacitance
Impedance
Frequency
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A. Inductance
Inductance is measured in henrys. Capacitance, the property most often swapped with it, is measured in farads.
Reference: Basic electrical units
What is the usual difference between the transmit and receive frequencies of a repeater on the 2 meter band?
100 kHz
1.6 MHz
5 MHz
600 kHz
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D. 600 kHz
The standard 2 meter repeater offset is plus or minus 600 kHz. 5 MHz is the usual offset on 70 centimeters and 1.6 MHz is used on the 1.25 meter band.
Reference: Band plan conventions: repeater offsets
Which property of a radio wave defines its polarization?
The orientation of its magnetic field
The direction in which it travels
The ratio of its two field strengths
The orientation of its electric field
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D. The orientation of its electric field
Polarization is named for the direction of the electric field, so a vertical antenna produces a vertically polarized wave. The magnetic field is at right angles to it and is not the reference.