Quiz11spring2004

# Quiz11spring2004 - ENSC 3313, Spring 2004 Quiz 11-ANSWERS...

This preview shows pages 1–2. Sign up to view the full content.

ENSC 3313, Spring 2004 Quiz 11-ANSWERS Name ________________________________ Answer any 4 questions only , 1 point each 1. The resistivity of pure copper is ~1.7 × 10 -8 -m at room temperature and ~0.9 × 10 -8 -m at -100 o C. Explain. This is an illustration of the temperature dependence of electron mobility on temperature. At higher temperatures, more thermal vibrations cause more scattering events which in turn lower electron mobility and increase resistivity. Conversely, lower temperatures reduce thermal vibrations and raise electron mobility, hence reducing the resistivity. 2. I've designed a capacitor using aluminum oxide which has a dielectric constant of 3, the capacitance is too low. How much of an increase in dielectric constant would I need to increase the capacitance by 500%? The capacitance is given by: C=Q/V, or in geometry independent terms: ε r =D/E. Thus the relationship between the dielectric constant ε r and C is: C = ε r A/d, where A is the capacitor area and d is the

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 01/10/2012 for the course ENSC 3313 taught by Professor Staff during the Fall '11 term at Oklahoma State.

### Page1 / 2

Quiz11spring2004 - ENSC 3313, Spring 2004 Quiz 11-ANSWERS...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online