Answered: Find the diameter in inches of 3000ft…

Delmar's Standard Textbook Of Electricity

7th Edition

ISBN:9781337900348

Author:Stephen L. Herman

Publisher:Stephen L. Herman

Chapter9: Measuring Instruments

Section: Chapter Questions

Problem 5PP: 5. A digital voltmeter indicates a voltage of 2.5 V when 10 of current flow through a resistor....

See similar textbooks

Related questions

Concept explainers

Question

100%

Find the diameter in inches of 3000ft of copper wire that has a resistance of 77.78Ω

Expert Solution

Step 1

Given:

Length of copper wire,

$\begin{array}{rcl} l & = & 3000 ft \\ = & 914.4 m \end{array}$

Resistance, $R = 77.78 Ω$

Step 2

The resistivity of copper is given as $ρ = 1.724 \times 10^{- 8} Ωm$

$\begin{array}{rcl} R & = & \frac{ρ l}{A} \\ R & = & \frac{ρ l}{π r^{2}} \\ 77.78 & = & \frac{1.724 \times 10^{- 8} \times 914.4}{π \times r^{2}} \\ r^{2} & = & \frac{1.724 \times 10^{- 8} \times 914.4}{π \times 77.78} \\ r & = & \sqrt{6.45143 \times 10^{- 8}} m \\ r & = & 2.54 \times 10^{- 4} m \end{array}$

Step by step

Solved in 4 steps

Knowledge Booster

Learn more about

Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, electrical-engineering and related others by exploring similar questions and additional content below.

Similar questions