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You are working as an electrical technician. One day, out in CR the field, you need an inductor but cannot find one. Look- ing in your wire supply cabinet, you find a cardboard tube with single-conductor wire wrapped uniformly around it to form a solenoid. You carefully count the turns of wire and find that there are 580 turns. The diameter of the tube is 8.00 cm, and the length of the wire-wrapped portion is 36.0 cm. You pull out your calculator to determine:

a. the inductance of the coil
b. the emf generated in it if the current in the wire increases at the rate of 4.00 A/s.

User Legends
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1 Answer

6 votes
6 votes

Step-by-step explanation:

Given info: The Number of turns in the wire is 580 the diameter of

tube is
8.00 \mathrm{~cm} and the length of the tube up to which wire is wrapped is
36.0 \mathrm{~cm}.

Formula to calculate the inductance of the coil is,


L=(\mu_(0) N^(2) A)/(l)

Here,


L is inductance of the coil.


\mu_(0) is the permittivity.


N is the number of turns.


l is the length up to which wire is wrapped.


A is the cross sectional area of the coil.

The expression for the area is,


A=(\pi d^(2))/(4)

Substitute
(\pi d^(2))/(4)[tex] for [tex]A in equation (1).


L=(\left(\mu_(0) N^(2)\right) (d d^(2))/(4))/(l)

Substitute 580 for
N, 4 \pi * 10^(-7)[tex] for [tex]\mu_(0), 8.00 \mathrm{~cm}[tex] for [tex]d[tex] and [tex]36.0 \mathrm{~cm}[tex] for [tex]l .


\begin{array}{c} &nbsp;</p><p>=\frac{4 \pi * 10^(-7) * 580 * 580 * \frac{x(8.00 \mathrm{~cm} * 8.00 \mathrm{~cm})}{4}}{36 \mathrm{~cm}} \\ &nbsp;</p><p>=5.90 \mathrm{mH} &nbsp;</p><p>\end{array}

Conclusion:

Therefore, the inductance of the given single conductor wire is


5.90 \mathrm{mH} .

Given info: The rate of increasing current
4.00 \mathrm{~A} / \mathrm{s} and the inductance of the coil
5.90 \mathrm{mH}.

The generated emf is,


</p><p>\varepsilon=L (d i)/(d t) </p><p>

Here,


\varepsilon is the generated emf.


L[tex] is the inductance of the coil. </p><p>[tex](d i)/(d t)[tex] is the rate of change of current. </p><p>Substitute [tex]5.90 \mathrm{mH}[tex] for [tex]L[tex] and [tex]4.00 \mathrm{~A} / \mathrm{s}[tex] for [tex](d i)/(d t)


\begin{array}{c} </p><p>\varepsilon=5.90 \mathrm{mH} * 4.00 \mathrm{~A} / \mathrm{s} \\ </p><p>= &amp; 23.6 \mathrm{mV} </p><p>\end{array}

Conclusion:

Therefore, the generated emf is
23.6 \mathrm{mV}.

User Sigurd
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