# Electronics and Communication Engineering - Electronic Devices and Circuits - Discussion

Discussion Forum : Electronic Devices and Circuits - Section 2 (Q.No. 5)
5.
Calculate the resistivity of n-type semiconductor from the following data, Density of holes = 5 x 1012 cm-3. Density of electrons = 8 x 1013 cm-3, mobility of conduction electron = 2.3 x 104 cm2/ V-sec and mobility of holes = 100 cm2/V-sec.
0.43 Ω-m
0.34 Ω-m
0.42 Ω-m
0.24 Ω-m
Explanation:

Resistivity(r) = .

σ = e(neue + nnun).

Discussion:
13 comments Page 1 of 2.

Jidsa said:   4 years ago
@Psalmer Since cm is in the denominator before getting the reciprocal of it for the resistivity, you must multiply it by 100 to convert it to the meter.
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Psalmer said:   4 years ago
@Lik When you want to convert the cm to meter, it must be divided by 100 and not multiply.
0.29488cm x (1m/100cm).

Lyle said:   5 years ago
Thanks @Lik.

Lik said:   5 years ago
Conductivity= 1.6x10^-19 * (5x10^12 * 100 + 8x10^13 * 2.3x10^4) = 0.29488.
Since this is in cm multiply it by 100 to get value in m which is 29.488,
Resistivity = 1/conductivity,
Resistivity = 0.034 ohm-meter.
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Siddharth said:   5 years ago
Here e = 1.6*10^-19 and n represents holes.

Keerthana said:   6 years ago
(1)

Senthil said:   6 years ago

Naresh said:   6 years ago