MCQOPTIONS
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MCQOPTIONS
This section includes 5 Mcqs, each offering curated multiple-choice questions to sharpen your General Awareness knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Diffusion through grain boundaries is very fast and is called short-circuit diffusion. |
| A. | Assertion: Their contribution to overall diffusion is negligible. |
| B. | True |
| C. | False |
| Answer» B. True | |
| 2. |
Following plot shows the concentration profile at two different time, T1 and T2 for the same non-steady diffusion process. |
| A. | What is the correct relationship between the two? |
| B. | T1 > T2 |
| C. | T2 > T1 |
| D. | Insufficient data |
| E. | Same process can’t have two concentration profiles |
| Answer» C. T2 > T1 | |
| 3. |
Predeposition and drive-in diffusion are two heat treatments used in the manufacture of integrated circuits. |
| A. | Assertion: Predepostion is carried at a higher temperature than drive-in diffusion. |
| B. | True |
| C. | False |
| Answer» C. False | |
| 4. |
If C is the concentration of the diffusing species at distance x from the source and time t, then according to Fick’s second law (assuming diffusion coefficient, D is constant): |
| A. | ∂C/∂x = D.(∂C/∂t) |
| B. | ∂C/∂t = D.(∂2C/∂x2) |
| C. | ∂C/∂x = D.(∂2C/∂t2) |
| D. | ∂C/∂t = D.(∂C/∂x) |
| Answer» C. ∂C/∂x = D.(∂2C/∂t2) | |
| 5. |
Concentration of hydrogen gas across a 2mm thick palladium sheet differs by 4 kg/m3. Considering steady-state diffusion with diffusion constant 10-10 m2/s, diffusion flux is ______ kg/m2.s: |
| A. | 2 x 1010 |
| B. | 2 x 10-10 |
| C. | 5 x 10-11 |
| D. | 5 x 109 |
| Answer» C. 5 x 10-11 | |