Discussion
Home ‣ Electronics and Communication Engineering ‣ Materials and Components Comments
- Question
In metals, the average drift velocity of electron per unit field is called mobility.
Options- A. True
- B. False
- Correct Answer
- True
- 1. In metals the thermal conductivity K and electrical conductivity ? are related as (K/?T) = L, L is known as
Options- A. Lattice constant
- B. Lorentz number
- C. Lanevin function
- D. Larmor number Discuss
- 2. When a material becomes a superconductor, its resistivity becomes
Options- A. very small
- B. zero
- C. about 10% of normal value
- D. about 20% of normal value Discuss
- 3. As the temperature of a pure silicon specimen is increased
Options- A. the number of free electrons increases
- B. the number of holes decreases
- C. the number of holes increases
- D. the number of free electrons and holes increases Discuss
- 4. Match the following:
List I (type of controller) List II (Operation) A. Pneumatic controller 1. Flexible operation B. Hydraulic controller 2. High torque high speed operation C. Electronic controller 3. Fire and explosion proof operation
Options- A. A-1, B-3, C-2
- B. A-1, B-2, C-3
- C. A-3, B-1, C-2
- D. A-3, B-2, C-1 Discuss
- 5. Match the following:
List I (Operator) List II (Description) A. & & 1. Assignment B. | | 2. Logical AND C. = 3. Logical OR
Options- A. A-1, B-2, C-3
- B. A-2, B-3, C-1
- C. A-3, B-2, C-1
- D. A-1, B-3, C-2 Discuss
- 6. Silicon and germanium atoms combine orderly into array of atoms located in repetitive geometric pattern. This pattern is called
Options- A. crystal
- B. covalent bond
- C. molecule
- D. valence bond Discuss
- 7. Dielectric constant of transformer oil is about
Options- A. 1
- B. 4
- C. 10
- D. 20 Discuss
- 8. In carbon resistor colour code, the third band is red. It indicates
Options- A. two zeros
- B. three zeros
- C. multiplier is 0.01
- D. multiplier is 0.1 Discuss
- 9. Assertion (A): In many materials, dielectric polarization causes mechanical distortion.
Reason (R): If dielectric polarization causes mechanical distortion then mechanical distortion must cause dielectric polarization.
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 Discuss
- 10. Consider the following statement
If an electric field is applied to an n type semiconductor bar, the electrons and holes move in opposite directions due to their opposite charges. The net currents is- both due to electrons and holes with electrons as majority carriers
- sum of hole and electron currents
- difference between electron and hole currents.
Options- A. 1 only
- B. 1 and 2
- C. 2 only
- D. 3 only Discuss
Materials and Components problems
Search Results
Correct Answer: Lorentz number
Correct Answer: zero
Explanation:
A superconductor has zero resistance.
Correct Answer: the number of free electrons and holes increases
Correct Answer: A-3, B-2, C-1
Correct Answer: A-2, B-3, C-1
Correct Answer: crystal
Correct Answer: 4
Correct Answer: two zeros
Correct Answer: A is true but R is false
Correct Answer: 1 and 2
Explanation:
The net current is sum of currents due to holes and electrons.
In n type materials, electrons are majority carriers.
Comments
There are no comments.More in Electronics and Communication Engineering:
Programming
Copyright ©CuriousTab. All rights reserved.