
The temperature dependence of resistivity of a semiconductor is represented by:
A)
B)
C)
D)




Answer
468.6k+ views
Hint: The resistivity of a substance is a quantitative measurement of the tendency of the substance to prevent current flowing from it. The resistivity of the substance is directly proportional to the resistance of the substance.
Complete answer:
The resistance of a substance is decided by the number of charge carriers in the substance and how they are affected by the change in temperature. The number of charge carriers in semiconductors is more than that of insulators but is less than that of conductors. This implies that for a given temperature, the resistivity of a semiconductor is less than that of insulators but higher than that of metals.
Now, when the temperature of the semiconductor is increased, the electrons start vibrating due to thermal energy. This leads to the generation of more free electrons and more holes. These carriers are generated by the thermal breaking of bonds inside the substance. Thus, as the temperature rises, a greater number of covalent bonds break in the substance, releasing more electrons which lower the resistivity rapidly as there are now more free charges available to carry the current. This temperature dependence is usually exponential which makes semiconductors very useful in electronic circuits detecting small temperature changes.
Hence the correct choice will be option (B).
Note:
To answer such questions, we must be aware of the current-carrying mechanism in a semiconductor and how it will be affected by thermal energy. The decreasing resistivity of semiconductors with increasing temperatures can also be thought of as it has a negative temperature coefficient of resistance.
Complete answer:
The resistance of a substance is decided by the number of charge carriers in the substance and how they are affected by the change in temperature. The number of charge carriers in semiconductors is more than that of insulators but is less than that of conductors. This implies that for a given temperature, the resistivity of a semiconductor is less than that of insulators but higher than that of metals.
Now, when the temperature of the semiconductor is increased, the electrons start vibrating due to thermal energy. This leads to the generation of more free electrons and more holes. These carriers are generated by the thermal breaking of bonds inside the substance. Thus, as the temperature rises, a greater number of covalent bonds break in the substance, releasing more electrons which lower the resistivity rapidly as there are now more free charges available to carry the current. This temperature dependence is usually exponential which makes semiconductors very useful in electronic circuits detecting small temperature changes.
Hence the correct choice will be option (B).
Note:
To answer such questions, we must be aware of the current-carrying mechanism in a semiconductor and how it will be affected by thermal energy. The decreasing resistivity of semiconductors with increasing temperatures can also be thought of as it has a negative temperature coefficient of resistance.
Recently Updated Pages
Express the following as a fraction and simplify a class 7 maths CBSE

The length and width of a rectangle are in ratio of class 7 maths CBSE

The ratio of the income to the expenditure of a family class 7 maths CBSE

How do you write 025 million in scientific notatio class 7 maths CBSE

How do you convert 295 meters per second to kilometers class 7 maths CBSE

Write the following in Roman numerals 25819 class 7 maths CBSE

Trending doubts
Give 10 examples of unisexual and bisexual flowers

Draw a labelled sketch of the human eye class 12 physics CBSE

Differentiate between homogeneous and heterogeneous class 12 chemistry CBSE

Differentiate between insitu conservation and exsitu class 12 biology CBSE

What are the major means of transport Explain each class 12 social science CBSE

Draw a diagram of a flower and name the parts class 12 biology ICSE
