Answer:
a) 0.01558 Ω per 1000 feet
b) 0.0923 Ω per mile
c) 3.57%
Explanation:
<u>a) Calculate and verify the DC resistance </u>
Dc resistance = R = р
for aluminum at 20°C
р = 17 Ωcmil/ft
hence R = 17 * 1000 / ( 113000 ) = 0.01527 Ω per 1000 feet
there when there is an increase in resistance of 2% spiraling
R = 1.02 * 0.01527 = 0.01558 Ω per 1000 feet
<u>b) Calculate the DC resistance at 50°C </u>
R2 = R1 ( )
where ; R1 = 0.01558 , T = 228 , t2 = 50, t1 = 20 ( input values into equation above )
hence R2 = ( 0.01746 / 0.189 ) Ω per mile = 0.0923 Ω per mile
<u>c ) Determine the percentage increase due to skin effect </u>
AC resistance = 0.0956 ohm per mile
Hence; Increase in skin effect
= ( 0.0956 -0.0923 ) / 0.0923
= 0.0357 ≈ 3.57%
Answer:The move from hubs (shared networks) to switched networks was a big improvement. Control over collisions, increased throughput, and the additional features offered by switches all provide ample incentive to upgrade infrastructure. But Layer 2 switched topologies are not without their difficulties. Extensive flat topologies can create congested broadcast domains and can involve compromises with security, redundancy, and load balancing. These issues can be mitigated through the use of virtual local area networks, or VLANs. This chapter provides the structure and operation of VLANs as standardized in IEEE 802.1Q. This discussion will include trunking methods used for interconnecting devices on VLANs.
Problem: Big Broadcast Domains
With any single shared media LAN segment, transmissions propagate through the entire segment. As traffic activity increases, more collisions occur and transmitting nodes must back off and wait before attempting the transmission again. While the collision is cleared, other nodes must also wait, further increasing congestion on the LAN segment.
The left side of Figure 4-1 depicts a small network in which PC 2 and PC 4 attempt transmissions at the same time. The frames propagate away from the computers, eventually colliding with each other somewhere in between the two nodes as shown on the right. The increased voltage and power then propagate away from the scene of the collision. Note that the collision does not continue past the switches on either end. These are the boundaries of the collision domain. This is one of the primary reasons for switches replacing hubs. Hubs (and access points) simply do not scale well as network traffic increases.
Answer:
soon
Explanation:
because soon is like past tense for prepaid
Answer:
The solid rod BC has a diameter of 30 mm and is made of an aluminum for which the allowable shearing stress is 25 MPa. Rod AB is hollow and has an outer diameter of 25 mm; it is made of a brass for which the allowable shearing stress is 50 MPa.