# Electronics and Communication Engineering - Materials and Components

### Exercise :: Materials and Components - Section 5

1.

Assertion (A): Intrinsic resistivity of silicon is lower than that of germanium.

Reason (R): Magnitude of free electron concentration in germanium is more than that of silicon.

 A. Both A and R are true and R is correct explanation of A B. Both A and R are true but R is not correct explanation of A C. A is true but R is false D. A is false but R is true

Explanation:

No answer description available for this question. Let us discuss.

2.

The units for ∈r are

 A. Farads B. Farads/m C. D. no units

Explanation:

r is only a numeric. Hence no units.

3.

The real part of complex dielectric constant and tanδ for a dielectric are 2.1 and 5 x 10-4 at 100 Hz respectively. The imaginary part of dielectric constant at 100 Hz is

 A. 1.05 x 10-3 B. 2.1 x 10-3 C. 5 x 10-3 D. 1.05 x 10-2

Explanation: 4.

A copper atom is neutral. Its core has a net charge of

 A. 0 B. + 1 C. - 1 D. + 2

Explanation:

No answer description available for this question. Let us discuss.

5.

As the temperature of semiconductor is increased

 A. the average number of free charge carriers decreases B. the average number of free charge carriers increases C. the average number of free charge carriers remains the same D. the average number of free charge carriers may increase or decrease