More problems, in prep for final.

Final topics:

circuit basics (series, parallel, power, current, voltage, resistance)

combination circuits

magnetism, electromagnetism, electromagnetic induction

special theory of relativity

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1. Find the charge that "flows" past a given point, if a 12-V battery is in series with a 3-ohm resistor.

2. Consider 4 identical resistors, connected to a power supply. Two are in series, and these are connected to two that are in parallel. If each resistor is a light bulb, which one(s) are brightest? (Hint: Consider the equation for power, particularly P = i^2 R)

3. In the above problem, if one of the series "bulbs" are removed, what happens to the brightness of all of them? If one of the parallel bulbs are removed, what happens to the brightness of all of them?

4. Review the meaning and subtleties of magnetic fields, especially what compasses do in a magnetic field.

5. Consider a coil (100 turns) of wire, with a radius of 0.1-m. A magnetic field increases from 0-20 T in 5 seconds, directly onto the coil. What voltage is induced?

6. Distinguish between motors and generators.

7. Distinguish between speakers and microphones.

8. Imagine two twins: Earthy and Spacey. Earthy stays home, while Spacey travels at 0.5c to a star system 5 light-years away. How long will this trip last according to each twin? There are two answers for this question. Also, leave the distance (5 light-years) in light-years (or c-years). This makes the time work out to years, and in general, makes the math much easier. No conversions to do.