# Question - Communications



## Kipper (Sep 5, 2006)

A commercial-grade coaxial cable (RG-58) has been measured and found to exhibit the following characteristics at 100MHz:

R = 0.79 ohms/meter = 1271.38 ohms/mile

L = 0.262 microhenrys/meter = 421.65 microhenrys/mile

G = 1.93 x 10^-6 mhos/meter = 3.106 x 10^-3 siemens/mile

C = 96.8 picofarads/meter = 0.15578 microfarads/mile

For this line, calculate the following:

Attenuation constant

a. 12.2994 nepers/mile

b. 12.2994 db/mile

c. 12.2994 nepers/meter

d. 12.2994 db/meter

Phase constant

a. 5091.7229 radians/meter

b. 3.1642 radians/meter

c. 3.1642 radians/mile

d. 5091.7229 radians/foot

Characteristic impedance

a. 50 ohms

b. 300 ohms

c. 52 ohms

d. 72 ohms

Velocity of propagation

a. 123,400 miles/hour

b. 123,400 meters/sec

c. 123400 miles/sec

d. 123400 km/sec

Wavelength

a. 2 meters

b. 20 meters

c. 200 meters

d. 2000 meters

This is problems 3.4-3.8 in the KAPLAN book. Great study reference if you do not already have it.


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## CiceroKid (Sep 27, 2006)

The multi-part format of this question does not match what is now on the exam. Each 4-mutliple-choice problem should be stand-alone.

This is not my field, so I can't comment on the questions themselves.

Kid


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## Hill William (Sep 28, 2006)

> The multi-part format of this question does not match what is now on the exam. Each 4-mutliple-choice problem should be stand-alone.
> This is not my field, so I can't comment on the questions themselves.
> 
> Kid


You are correct that this does not follow the current exam format. But for you guys studying, you need to do problems like this so that if part I, II, III, etc. are on the test, you will have seen it. Problems Problems Problems.


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## Wolverine (Oct 12, 2006)

Answers?


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## Frontier05 (Oct 12, 2006)

> Answers?


yep.

Attn Const: a

Phase Const b

Charact imp: c

veloc prob c

wavelen a


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