Electronics and Communication Engineering - Materials and Components

6.
With increase in temperature, the electrical conductivity would
increase in metals as well as in intrinsic semiconductor
increase in metals but decrease in intrinsic semiconductor
decrease in metals but increase in intrinsic semiconductor
decrease in metals as well as in intrinsic semiconductor
Answer: Option
Explanation:

Increase in temperature causes resistivity of metals to increase and resistivity of intrinsic semiconductors to decrease.

Conductivity is reciprocal of resistivity.


7.
An electron for which l = 0 has zero orbital magnetic dipole moment.
True
False
Answer: Option
Explanation:
No answer description is available. Let's discuss.

8.
The resistance of a metallic wire would
increase as f increase
decrease as f increase
remains the same at all frequencies
increase with f up to a certain frequency and then decrease
Answer: Option
Explanation:

As increases the resistance increases due to skin effect.


9.
If a small amount of Cu is added to Ni conductor, then
resistivity of Ni will decrease at all temperatures because Cu is a better conductor than Ni
residual resistivity of Ni at low temperature will increase as Cu atoms act as defect centres
resistivity of Ni will increase at all temperatures as Cu destroys the periodicity of Ni and acts as defects
resistivity of Ni remains the same
Answer: Option
Explanation:
No answer description is available. Let's discuss.

10.
When a dielectric material is subjected to alternating field, the absorption of energy by the material from the field is given by the imaginary part of polarizability.
True
False
Answer: Option
Explanation:
No answer description is available. Let's discuss.