Shock Value B/Circuit Lab C

Locked
Jim_R
Admin Emeritus
Admin Emeritus
Posts: 283
Joined: May 13th, 2001, 4:22 pm
Division: Grad
Has thanked: 0
Been thanked: 1 time
Contact:

Shock Value B/Circuit Lab C

Post by Jim_R »

-The path of the Administrator is beset on all sides by the inequities of the selfish and the tyranny of evil men.

-Nothing\'s gonna get deleted. We\'re gonna be like three little Fonzies here. And what\'s Fonzie like? Come on, what\'s Fonzie like?
-Cool?
-Correctamundo. And that\'s what we\'re gonna be. We\'re gonna be cool. Now, I\'m gonna count to three, and when I count three, you let go of your mouse, and back away from the keyboard. But when you do it, you do it cool. Ready? One... two... three.
GuyFromNowhere
Member
Member
Posts: 2
Joined: July 28th, 2013, 8:16 pm
Division: C
State: IL
Has thanked: 0
Been thanked: 0

Re: Shock Value B/Circuit Lab C

Post by GuyFromNowhere »

Hello, Shock Valuers! Super excited for this event this year.
Quick question about a Thevenin equivalent problem. At JS Gandora's circuit lab test at the test exchange, there is a Thevenin equivalent problem. Setting Node B as the ground, I used nodal analysis to get that Node A has voltage of 4 and node at the far right connected to the branches with 3 ohm, 1 ohm, and 2 ohm resistors (let's just call as node c) has 6 volts.
The answer says that the Thevenin voltage is 3/8 V. (The voltage diff between A and B) could someone set me straight here? On the bright side, I'm getting a correct Thevenin resistance.
Thanks.
User avatar
tangentline
Member
Member
Posts: 30
Joined: September 29th, 2012, 6:17 pm
Division: Grad
State: CA
Has thanked: 0
Been thanked: 0

Re: Shock Value B/Circuit Lab C

Post by tangentline »

@Guyfromnowhere:
Your answer is presumably correct.
I did the problem with both the node voltage and superposition methods and came out to 4V.
The resistance of thevenin is indeed 15/8 ohms.
As far as confirmation, I used a "test" load resistor of 1 ohms and compared the respective current/voltage drop of the thevenin circuit and the actual circuit on that branch are the same with a thevenin voltage of 4V
The closest I can get to 3/8 is ignoring the current source and getting 5/8 V...
Last edited by tangentline on September 29th, 2013, 6:47 pm, edited 1 time in total.
JSGandora
Member
Member
Posts: 613
Joined: December 25th, 2010, 12:09 pm
Division: C
State: NJ
Has thanked: 0
Been thanked: 0

Re: Shock Value B/Circuit Lab C

Post by JSGandora »

I probably made an arithmetic mistake there, I made the answer key somewhat in haste. You are most likely correct.
GuyFromNowhere
Member
Member
Posts: 2
Joined: July 28th, 2013, 8:16 pm
Division: C
State: IL
Has thanked: 0
Been thanked: 0

Re: Shock Value B/Circuit Lab C

Post by GuyFromNowhere »

Okay, thanks so much! Just wanted to make sure!
Je suis K
Member
Member
Posts: 21
Joined: August 10th, 2013, 6:46 am
Division: C
State: MN
Has thanked: 0
Been thanked: 0

Re: Shock Value B/Circuit Lab C

Post by Je suis K »

what should I know for the "Practical" section?
Jdogg
Member
Member
Posts: 169
Joined: May 19th, 2011, 6:00 pm
Division: Grad
State: PA
Has thanked: 0
Been thanked: 0

Re: Shock Value B/Circuit Lab C

Post by Jdogg »

Je suis K wrote:what should I know for the "Practical" section?
You should be able to take your knowledge on the "test" portion and apply that to "lab" like questions. But you should also know how to operate a voltmeter, read resistor values, etc....
For example you might be given a RC circuit and asked to solve for the Capacitor's capacitance given a voltmeter, a switch, and a stopwatch while knowing the resistor and voltage of the battery (assumed to be ideal for small loads).
Harriton Class of 2013
Vice-Deputy of Avionics and Control for Lunar Lion
Assistant Coach of State College High School
transcience
Member
Member
Posts: 3
Joined: October 16th, 2013, 7:05 pm
Division: B
State: NE
Has thanked: 0
Been thanked: 0

Re: Shock Value B/Circuit Lab C

Post by transcience »

Can anyone make a list of website to study from?
Je suis K
Member
Member
Posts: 21
Joined: August 10th, 2013, 6:46 am
Division: C
State: MN
Has thanked: 0
Been thanked: 0

Re: Shock Value B/Circuit Lab C

Post by Je suis K »

How do we practice the "practical" section? Should I just try to light up a light bulb with a wire? I know last year at the wright state invitational they had a really difficult (at least to me and my partner) practical section. Any advice?
Bozongle
Member
Member
Posts: 76
Joined: January 20th, 2013, 12:41 pm
Division: B
State: IN
Has thanked: 0
Been thanked: 0

Re: Shock Value B/Circuit Lab C

Post by Bozongle »

Je suis K wrote:How do we practice the "practical" section? Should I just try to light up a light bulb with a wire? I know last year at the wright state invitational they had a really difficult (at least to me and my partner) practical section. Any advice?
Based off what I've seen, the practical section can be anything from the theoretical section except in real-life form. So, you still might have to solve problems, along with measuring, building, and following through certain directions. Although, read the rules to see what exactly you might see at competition. But be prepared for anything. Build series circuits, parallel circuits, combination of both, and other complex circuits. Use switches, resistors, variable resistors, etc. Measure everything you build, use Ohm's Law to find Voltage, Current, and Resistance. Build a circuit with a bulb and try to make the bulb the dimmest possible without it completely going out, and then try to make it as bright as possible. Repeat with a combination of bulbs, resistors, wire lengths, etc. Build an electromagnet, and even on one competition test you were supposed to build a simple motor based on materials given. Also, based on what you have, use different materials to build circuits. For example, get used to using a breadboard, and also alligator clips, and the "generic" copper wire. Just like any other practical lab event, practice helps the most.
Locked

Return to “2014 Lab Events”

Who is online

Users browsing this forum: No registered users and 3 guests