Concepts Of Physics MCQ Edition [Volume 2]

Exam: Concepts Of Physics MCQ Edition [Volume 2]
Subject: Physics
Chapter: Semiconductors and Semiconductor Devices

Concepts Of Physics MCQ Edition [Volume 2] · Physics · Semiconductors and Semiconductor Devices

The drift current in a p - n junction is given to be 20.0 ....

The drift current in a

p

n

junction is given to be

20.0 \mu\text{A}

. Estimate the number of electrons crossing a cross section per second within the depletion region.

Options

A $2.50 \times 10^{14}$
B $3.12 \times 10^{13}$
C $6.25 \times 10^{13}$
D $1.25 \times 10^{14}$

Correct answer

C. $6.25 \times 10^{13}$

Step-by-step solution

o estimate the number of electrons, we assume that electrons and holes contribute equally to the drift current. Thus, the current due to electrons is:

I_e = \dfrac{I}{2} = 10.0 \mu\text{A} = 10.0 \times 10^{-6} \text{ A}

The number of electrons crossing the cross-section per second is:

n = \dfrac{I_e}{e}

n = \dfrac{10.0 \times 10^{-6}}{1.6 \times 10^{-19}}

n = 6.25 \times 10^{13}

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