Chapter 27: Q. 1 (page 762)

$1.0 \times 10^{20}$ electrons flow through a cross-section of a $2.0 mm$ diameter iron wire in $5.0 s$ . What is the electron drift speed?

Short Answer

Expert verified

The electron drift speed is $75 μ m / s .$

Step by step solution

Given Information

Number of electrons flow through $= 1.0 \times 10^{20}$

Diameter $= 2.0 m m$

Time $= 5.0 s$

Explanation

The definition of the electron current includes the electron drift speed, which can be expressed as:

$i_{e} = n_{e} A v_{d} \Rightarrow v_{d} = \frac{i_{e}}{n_{e} A}$

The electron current is just the number of electrons per unit time,

$i_{e} = \frac{N_{e}}{t}$

The area of the cross-section, since the latter is a circle, will be

$A = \frac{π D^{2}}{4}$

Combining, we can find

$v_{d} = \frac{N_{e} / t}{n_{e} π D^{2} / 4} = \frac{4 N_{e}}{π n_{e} t D^{2}}$

Substitute the values,

role="math" localid="1648798324977" $v_{d} = (\frac{4 \times 10^{20} e}{π \cdot 8.5 \cdot 10^{28} e \times 5 s \times 0.002 m m^{2}})$

$= 7.5 \cdot 10^{- 5} m / s .$

Final Answer

Hence, the electron drift speed is $75 μ m / s .$

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$1.0 \times 10^{20}$ electrons flow through a cross-section of a $2.0 mm$ diameter iron wire in $5.0 s$ . What is the electron drift speed?

Short Answer

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1.0×1020electrons flow through a cross-section of a 2.0mmdiameter iron wire in 5.0s. What is the electron drift speed?

Short Answer

Step by step solution

Given Information

Explanation

Final Answer

One App. One Place for Learning.

Most popular questions from this chapter

Recommended explanations on Physics Textbooks

Engineering Physics

Waves Physics

Fields in Physics

Medical Physics

Famous Physicists

Magnetism

Study anywhere. Anytime. Across all devices.

$1.0 \times 10^{20}$ electrons flow through a cross-section of a $2.0 mm$ diameter iron wire in $5.0 s$ . What is the electron drift speed?