EE 2212

PROBLEM SET 3

S. G. Burns

Due: 13 February 2013

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1. Text Problems 2.4 and 2.5 as a combination for two different metallization materials, Al and Cu. To this add: Find the current density if I=10mA.

2. A 100 watt incandescent light bulb typically uses AWG #18 wire (standard lamp cord) in the lighting fixture. AWG (American Wire Gauge) #18 has a diameter of 0.1024 cm.

(a) What is the current and current density in this wire?

(b) Compare the current density that you compute for Text Problems 2.4 and 2.5 with the current density in Part (a).

3. Rank the following materials from lowest resistivity, r, (1) to highest resistivity, r, (11). The posted conductivity chart discussed in class should be

helpful and you will have to look up a resistivity value for Gold.

_____Gold, _____Quartz, _____Tap water, _____Intrinsic Silicon, _____Gallium Arsenide, _______ Deionized water, _______Distilled Water ______Aluminum, _____Copper, _____Intrinsic Germanium, _____Silver

4. Compare the resistance of wires made from Cu, Ag, Au, and Al if each wire is 1 meter long and has a cross-sectional area of 1 mm² . Compute the

current and current densities if one volt is applied. What are the advantages and disadvantages of each material also taking into account the

economics of the selection.

5. Refer to the energy levels in the hydrogen atom. What is the photon wavelength for a transition between the -0.378 eV and 0.543 eV energy levels.

What is the relation to the optical spectrum?

6. Refer to Table 2.3 in the text. Compute the wavelength for a photon emitted from GaAs, GaN, and InP and indicate their relationship to the

optical spectrum. To this problem, provide numerical values in eV for a material band gap energy for a semiconductor device operating in:

(a) DVD players using blue LASERS (i.e. SONY BLU-RAY^TM DVDs or HD Format DVDs)

(b) A CD player solid-state LASER operating in the near-infrared

(c) LASER pointer operating in the red

Just so you don’t forget Ohm’s law

And this follows nicely with our starting Chapter 2

More Chapter 2 Support With A Bit Of Math To Help You Out