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Electronics and Communication Engineering - Materials and Components

Exercise : Materials and Components - Section 4
16.
For a given value (n) of principle quantum number, the number of possible electronic states are
n
n2
n3
n
Answer: Option
Explanation:

The total number of states corresponding to a given value of n is equal to

(2l + 1) = 1 + 3 + .... + [2(n-1) + 1] = n2.

17.
Electrical conductivity of metals expressed in ohm-1 m-1 is of the order of
1010
105
10-4
10-6
Answer: Option
Explanation:

Conductivity is reciprocal of resistivity. Since resistivity of metals is around 10-7 ohm-m, conductivity is about 107 ohm-1 m-1. So 105 is the nearest value.

18.
In a metal the probability of a state 0.1 eV below Fermi level being occupied
is more than the probability of state 0.1 eV above Fermi level being occupied
is the same as the probability of state 0.1 eV above Fermi level being occupied
is less than the probability of state 0.1 eV above Fermi level being occupied
may be equal to or more or less than the probability of state 0.1 eV above Fermi level being occupied
Answer: Option
Explanation:
No answer description is available. Let's discuss.
19.
An homogeneous dielectric material is subjected to an electric field E. If a small cavity is made inside the material, the electric field intensity inside and outside the cavity are different.
True
False
Answer: Option
Explanation:

The electric field intensity inside and outside the cavity are equal.

20.
A dielectric is subjected to alternating field. The dielectric losses are potential to
real part of dielectric constant
imaginary part of dielectric constant
both real and imaginary parts of dielectric constant
either real or imaginary part of dielectric constant
Answer: Option
Explanation:

Absorption of energy is proportional to imaginary part of complex dielectric constant.

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