materials-and-components electronics-and-communication-engineering question and answers -Page 3

CuriousTab

CuriousTab

Home Aptitude

Materials and Components problems

1. In metals the valence electron wave functions are strongly perturbed by the presence of neighbouring atoms.
Options
A. True
B. False

2. The core of a coil has a length of 10 cm. The self inductance is 8 mH. If the core length is doubled, all other quantities remaining the same, the self inductance will be
Options
A. 32 mH
B. 16 mH
C. 8 mH
D. 4 mH

3. Assertion (A): For a solenoid having N turns, .
Reason (R): For all magnetic materials, B increases linearly with I.
Options
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

4. The law J = ?E, where J is current density, ? is electrical conductivity and E is field strength is
Options
A. Ohm's law
B. Gauss law
C. Ampere's law
D. Biot-Savart law

5. If ?_r' and ?_r" are the real and imaginary parts of complex dielectric constant ?_r, and ? is the loss angle. Then
Options
A.
B.
C. tan ? = ?'?"
D. tan ? = 1 - ?'

7. Assertion (A): Silicon is less sensitive to changes in temperature than germanium.
Reason (R): Cut in voltage in silicon is less than that in germanium.
Options
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

10. The hysteresis phenomenon in ferromagnetic materials exists at all temperatures.
Options
A. True
B. False

First 3 4 5 ... 23 .. 42 43 Last

More in Electronics and Communication Engineering: