# 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 10^{12}cm^{-3}. Density of electrons = 8 x 10^{13}cm^{-3}, mobility of conduction electron = 2.3 x 10^{4}cm^{2}/ V-sec and mobility of holes = 100 cm^{2}/V-sec.Answer: Option

Explanation:

Resistivity(r) = .

σ = *e*(*n*_{e}*u*_{e} + *n*_{n}*u*_{n}).

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.

(1)

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).

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.

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.

(1)

Siddharth said:
5 years ago

Here e = 1.6*10^-19 and n represents holes.

Keerthana said:
6 years ago

Please explain the answer.

(1)

Senthil said:
6 years ago

Please explain the answer.

Naresh said:
6 years ago

Please explain the solution.

Sandhiya said:
7 years ago

Explain step wise, please.

Himans said:
7 years ago

I think the correct answer is actually 0.034 ohm-metre

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