Soo... Let's see if we can get someone else into this.
3 3 ohm resistors are in parallel and connected to a 5v battery. A fuse is in the battery that is rated for 4A. Will the fuse blow?
Re: Shock Value B/Circuit Lab C Question Marathon
Posted: September 9th, 2013, 5:25 pm
by FawnOnyx
Three 3 ohm resistors in parallel is 1/3 + 1/3 + 1/3 = 1/Req, so the equivalent resistance is 1 ohm. Ohm's law gives I = V/R = 5v/1ohm = 5 amps. Therefore the fuse will blow.
Re: Shock Value B/Circuit Lab C Question Marathon
Posted: September 9th, 2013, 5:56 pm
by iwonder
Awesome your turn!
Re: Shock Value B/Circuit Lab C Question Marathon
Posted: September 9th, 2013, 11:08 pm
by FawnOnyx
Wanted to do some logic gates since they sound interesting:
1. What will the output be if A is true and B,C, D are false?
2. What will the output be if A and B are false and C and D are true?
3. What will the output be if A,B,C, and D are all false?
Bonus: write a boolean algebra expression for the output in terms of A, B, C, and D
Not worth your time: make a truth table for this gate system
Disclaimer: I just looked up logic gates for the first time so I'm not sure if these questions are 100% legit.
Re: Shock Value B/Circuit Lab C Question Marathon
Posted: September 11th, 2013, 7:23 pm
by TwelveSquared
Ok, I waited since I virtually alternated answering every other question so far, but I'll go ahead.
I'm a programmer, so I can hopefully handle logic...
(although, i will note that i think the rules only cover DC, not digital logic. But it's still good practice anyway.)
Note: Since this is electronics, "true" is usually represented digitally as a 1 (or a high voltage, usually 5V), and false is 0(low voltage, usually 0V), which is what I'll use for the rest of this.
Problem 1:
Since A is high, the OR gate outputs high(1). Since both inputs in the NAND are low(0), it also outputs 1. These two bits are put into a NOR gate, resulting in 0.
Problem 2:
A and B are false, OR gate outputs 0. same output for the NAND. Since both inputs are 0, the NOR outputs 1, the total output.
Problem 3:
OR gate has same situation, outputs 0. the NAND outputs 1, when put through the NOR results in 0.
Boolean expression:
(I had to look this up...)
_____________
``````````__
(A + B) + (CD)
EDIT: Ignore all the ````. The site removed the whitespace when i tried to do it with spaces. The two lines represent NOT(inversion).
Re: Shock Value B/Circuit Lab C Question Marathon
Posted: September 11th, 2013, 8:42 pm
by FawnOnyx
Nice answer, looks right to me! Yeah writing boolean algebra on here isn't the easiest thing I guess.
I believe digital logic is a new theoretical topic this year, introduced in rule 3.d?
Re: Shock Value B/Circuit Lab C Question Marathon
Posted: September 11th, 2013, 9:13 pm
by iwonder
Yup. Boolean logic is new this year, limited to the exam portion of the event.
Re: Shock Value B/Circuit Lab C Question Marathon
Posted: September 13th, 2013, 8:02 pm
by TwelveSquared
iwonder wrote:Yup. Boolean logic is new this year, limited to the exam portion of the event.
Sweet!
(I will post the new question tomorrow, its already 10 where I'm at)
Re: Shock Value B/Circuit Lab C Question Marathon
Posted: September 14th, 2013, 9:50 am
by TwelveSquared
Alright, let's try this:
draw/CAD/etc. a Wheatstone bridge. Then state the equation used to find the resistance of an unknown resistor using it.
Re: Shock Value B/Circuit Lab C Question Marathon
Posted: October 15th, 2013, 6:13 pm
by TwelveSquared
TwelveSquared wrote:Alright, let's try this:
draw/CAD/etc. a Wheatstone bridge. Then state the equation used to find the resistance of an unknown resistor using it.
your turn!