An aluminum wire of diameter 2.6 mm carries a current of 12 A. How long on average does it take an electron to move \(12 \mathrm{m}\) along the wire? Assume 3.5 conduction electrons per aluminum atom. The mass density of aluminum is \(2.7 \mathrm{g} / \mathrm{cm}^{3}\) and its atomic mass is $27 \mathrm{g} / \mathrm{mol}$.

Short Answer

Expert verified
#tag_title#Step 3: Determine the charge transferred per second using the current value #tag_content#Now, we will determine the charge transferred per second using the current value of \(3.6 \mathrm{A}\). To do this, we will multiply the current by the charge of one electron: \(3.6 \mathrm{A} \times 1.6 \times 10^{-19} \mathrm{C} = 5.76 \times 10^{-19}\mathrm{C}\) This means that \(5.76 \times 10^{-19} \mathrm{C}\) is transferred per second through the wire. #tag_title#Step 4: Calculate the drift speed of an electron in the wire #tag_content#Now we can calculate the drift speed of an electron in the wire by dividing the charge transferred per second by the product of the number of free electrons per volume, cross-sectional area, and the charge of one electron: Drift speed \(=\frac{5.76 \times 10^{-19} \mathrm{C}}{(2.1077 \times 10^{26} \frac{\mathrm{electrons}}{\mathrm{m}^3})(5.31 \times 10^{-6} \mathrm{m}^2)(1.6 \times 10^{-19}\mathrm{C})} = 5.06 \times 10^{-5} \mathrm{m/s}\) This means that the drift speed of an electron in the wire is approximately \(5.06 \times 10^{-5} \mathrm{m/s}\). #tag_title#Step 5: Calculate the time it takes an electron to move \(12 \mathrm{m}\) along the wire #tag_content#Lastly, we will calculate the time it takes for an electron to move \(12 \mathrm{m}\) along the wire with the drift speed we just calculated. To do this, we will simply divide the distance by the speed: Time \(=\frac{12 \mathrm{m}}{5.06 \times 10^{-5} \mathrm{m/s}} = 2.37 \times 10^5 \mathrm{s}\) So, it takes approximately \(2.37 \times 10^5 \mathrm{s}\) for an electron to move \(12 \mathrm{m}\) along the wire. **In summary, it takes approximately \(2.37 \times 10^5 \mathrm{s}\) for an electron to move \(12 \mathrm{m}\) along the wire at a drift speed of \(5.06 \times 10^{-5} \mathrm{m/s}\).

Step by step solution

01

Calculate the cross-sectional area of the wire

To begin with, let's find the cross-sectional area of the wire using the diameter given. The formula for the area of a circle is \(A = \pi r^2\), where \(r\) is the radius of the wire. We will convert the diameter to meters and then divide it by 2 to find the radius. Diameter = \(2.6 \times 10^{-3} \mathrm{m}\) Radius = \(\frac{2.6 \times 10^{-3} \mathrm{m}}{2} = 1.3 \times 10^{-3} \mathrm{m}\) Now we can find the area: \(A = \pi (1.3 \times 10^{-3} \mathrm{m})^2 = 5.31 \times 10^{-6} \mathrm{m}^2\)
02

Calculate the number of free electrons in the wire

Next, we need to determine the number of free electrons in the wire. To do this, we will first find the number of aluminum atoms in a certain volume and then multiply that by the number of free electrons per atom (3.5 in this case). First, let's calculate the moles of aluminum atoms in \(1 \mathrm{m}^3\) of the wire using the mass-density value: \(\frac{2.7 \mathrm{g}}{\mathrm{cm}^3} \times \frac{1}{27} \frac{\mathrm{mol}}{\mathrm{g}} \times \frac{1000 \mathrm{cm}^3}{\mathrm{m}^3} = 100 \frac{\mathrm{mol}}{\mathrm{m}^3}\) Now we will multiply the moles by Avogadro's number to get the number of atoms: \(100 \frac{\mathrm{mol}}{\mathrm{m}^3} \times 6.022 \times 10^{23} \frac{\mathrm{atoms}}{\mathrm{mol}} = 6.022 \times 10^{25} \frac{\mathrm{atoms}}{\mathrm{m}^3}\) Finally, we will multiply the number of atoms by the number of free electrons per atom: \(6.022 \times 10^{25} \frac{\mathrm{atoms}}{\mathrm{m}^3} \times 3.5 \frac{\mathrm{electrons}}{\mathrm{atom}} = 2.1077 \times 10^{26} \frac{\mathrm{electrons}}{\mathrm{m}^3}\)

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

What is the energy stored in a small battery if it can move \(675 \mathrm{C}\) through a potential difference of \(1.20 \mathrm{V} ?\)
A current of \(10.0 \mathrm{A}\) is carried by a copper wire of diameter $1.00 \mathrm{mm} .\( If the density of the conduction electrons is \)8.47 \times 10^{28} \mathrm{m}^{-3},$ how long does it take for a conduction electron to move \(1.00 \mathrm{m}\) along the wire?
(a) What is the resistance of the heater element in a \(1500-\mathrm{W}\) hair dryer that plugs into a \(120-\mathrm{V}\) outlet? (b) What is the current through the hair dryer when it is turned on? (c) At a cost of \(\$ 0.10\) per kW .h, how much does it cost to run the hair dryer for 5.00 min? (d) If you were to take the hair dryer to Europe where the voltage is \(240 \mathrm{V},\) how much power would your hair dryer be using in the brief time before it is ruined? (e) What current would be flowing through the hair dryer during this time?
In the physics laboratory, Oscar measured the resistance between his hands to be \(2.0 \mathrm{k} \Omega .\) Being curious by nature, he then took hold of two conducting wires that were connected to the terminals of an emf with a terminal voltage of \(100.0 \mathrm{V} .\) (a) What current passes through Oscar? (b) If one of the conducting wires is grounded and the other has an alternate path to ground through a \(15-\Omega\) resistor (so that Oscar and the resistor are in parallel), how much current would pass through Oscar if the maximum current that can be drawn from the emf is \(1.00 \mathrm{A} ?\)
A Vespa scooter and a Toyota automobile might both use a \(12-\mathrm{V}\) battery, but the two batteries are of different sizes and can pump different amounts of charge. Suppose the scooter battery can pump 4.0 kC of charge and the automobile battery can pump \(30.0 \mathrm{kC}\) of charge. How much energy can each battery deliver, assuming the batteries are ideal?
See all solutions

Recommended explanations on Physics Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free