713quiz4sol

# 713quiz4sol - (a systems typically operate below a...

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713 Quiz 4: May 21st, 2004 Name:_______________________________ Circle the answer that is most correct. (i) A 10 MHz vertically polarized transmitter radiates groundwaves over soil with relative permittivity Find the numerical distance at a distance of 5 km from the transmitter. (a) 0.287 (b) 14.6 (c) 30.9 (d) 3621 (e) 17872 (ii) Which of the following statements are true about ground waves? (a) with all other parameters ﬁxed, horizontally polarized groundwaves attenuate more rapidly than vertically polarized groundwaves (b) increased ﬁeld strengths may not always be received as antenna heights are increased (c) the planar Earth theory of groundwaves predicts a transition from a 1/distance behavior for ﬁeld amplitudes to a 1/(distance squared) behavior (d) all of the abo v e (e) none of the above (iii) Which of the following is true about communication systems using tropospheric scatter?
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Unformatted text preview: (a) systems typically operate below a frequency of 100 MHz (b) lar ge antennas and high po wer transmitters are required (c) communications with signal bandwidths > 100 MHz are easily established (d) all of the above (e) none of the above (iv) In the Chapman theory of ionized atmospheric layers, which of the following is true? (a) the electron density of a recombination layer is minimum when the sun is directly overhead (b) the electron density of an attachment layer is minimum when the sun is directly overhead (c) the electron density of a recombination layer is a decreasing function of altitude (d) the electron density of an attachment layer is a decreasing function of altitude (e) none of the above 30 j 18. – p...
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## This note was uploaded on 10/25/2009 for the course ECE 713 taught by Professor Johnson,j during the Spring '08 term at Ohio State.

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