The Wiedemann-Franz law states that the ratio of thermal conductivity to electrical conductivity for a material is approximately constant, independent of the material for a fixed temperature. Moreover, as temperature changes, the ratio of thermal conductivity to electrical conductivity for a material is directly proportional to the temperature of the material. Which of the following is true of the Wiedemann-Franz law?

The Wiedemann-Franz law states that the ratio of thermal conductivity

1.	The Wiedemann-Franz law states that the ratio of thermal conductivity to electrical conductivity for a material is approximately constant, independent of the material for a fixed temperature. Moreover, as temperature changes, the ratio of thermal conductivity to electrical conductivity for a material is directly proportional to the temperature of the material. Which of the following is true of the Wiedemann-Franz law?
A.	(i) only
B.	(ii) only
C.	(ii) and (iii)
D.	(i), (ii), (iii) and (iv)
Answer» D. (i), (ii), (iii) and (iv)

Discussion

No Comment Found

Related MCQs

Consider the following functions: 1. To mask against diffusion or ion implant. 2. To act as a component in MOS devices. 3. To provide low resistivity paths. 4. To facilitate the entry of dopants. The functions of an oxide layer on a silicon wager would include:
Which of the following elements act as donor impurities? 1. Gold 2. Phosphorus 3. Boron 4. Antimony 5. Arsenic 6. Indium Select the correct answer using the codes given below:
The hysteresis loop of a magnetic material has an area of 5 cm2 with the scales given as 1 cm = 2 AT and 1 cm = 50 m Wb. At 50 Hz, the total hysteresis loss is:
Which of the following statements relate to the Hall effect? 1. A potential difference is developed across a currentcarrying metal strip when the strip is placed in a transverse magnetic field. 2. The Hall effect is very weak in metals but is large in semiconductors. 3. The Hall effect is very weak in semiconductors but large in metals. 4. It is applied in the measurement of the magnetic field intensity.Select the correct answer using the codes given below:
Which of the following statements are correct? 1. Superconductors are amorphous thin films of Be, Bi and Fe. 2. Soft superconductors observe Silsbee s rule. 3. Hard superconductors observe high critical field and transition temperature.
Consider the following statements: Impurity diffusion is used in semiconductor to control the conductivity. The nature of the impurity profile should be such that the 1. impurity concentration decreases with diffusion depth. 2. profile results in an internal electric field. 3. impurity concentration is homogeneous with no internal electric field. Which of these statements are correct?
Consider the following statements: In a transformer, the core material should have low 1. coercivity 2. retentivity 3. permeability Which of these statements are correct?
Which of the following statements are correct for ceramic materials? 1. They are inorganic substances. 2. They are brittle. 3. They are good thermal insulators. Select the correct answer using the codes given below:
Consider the following statements: The dielectric constant of an insulator depends on 1. applied voltage. 2. frequency of the alternating field applied. 3. temperature. 4. maximum current density in the insulator. Select the correct answer using the codes given below:
Electron mobility and life-time in a semiconductor at room temperature are respectively 0.36m2/(Vs) and 340 s. The diffusion length is:

Discussion

No Comment Found

Related MCQs

Reply to Comment