# Class Notes 3/28/16 - Physics Internal Website

```Physics 122 - Lecture
Date: 3/28/16
Questions?
Announcements/Reminders
Written HW #08 – Sulutions are online, in older
announcements.
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MP HW #09 – Due WEDNESDAY, 3/30, by 11:59 pm.
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Written HW #09 – Due WEDNESDAY, 3/30.

Reading assignment (check website) – Due on 3/30/16.
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EXAM 2 – April 1
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Cheat sheets ready for this week recitation!
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Last Class…
* Dielectrics;
Energy stored in capacitors;
Capacitors in circuits; equivalent capacitance.
…
Connect capacitor to a source to charge it ...
Clicker question
In the conducting wire, electrons are moving in the
direction from A to B. The electric field in the wire
A) points in the A-to-B direction.
B) points in the B-to-A direction.
C) is zero, since electric field inside a conductor is zero.
D) not enough information to tell.
Clicker question
In the conducting wire, electrons are moving in the
direction from A to B. The electric field in the wire
A) points in the A-to-B direction.
B) points in the B-to-A direction.
C) is zero, since electric field inside a conductor is zero.
D) not enough information to tell.
Current (Ch. 25)
Example 1:
Can a 2.2-mm-diameter copper wire have the same resistance as a
tungsten tungsten wire of the same length? Give numerical details.
Example 2:
A length of wire is cut in half and the two lengths are wrapped together
side by side to make a thicker wire. How does the resistance of this new
combination compare to the resistance of the original wire?
```