# 17.1 Maple Help

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## Questions 1, 2, 3 , 4

1. I = q/t

Conventional direction of the current runs opposite to electrons

2. V = R * I

In the direction of conventional the voltage drops

3. Vab = Ir

Terminal is

4. R = p * L/A or p = RA / L

Conventional direction of the current runs opposite to electrons

2. V = R * I

In the direction of conventional the voltage drops

3. Vab = Ir

Terminal is

__always__less than nominal4. R = p * L/A or p = RA / L

**kibakun**- Guest

## Re: 17.1 Maple Help

A 231.1 mA current flows through a 2.04 k resistor.

im put the mA into A's but why does it say 2.04

im put the mA into A's but why does it say 2.04

**k ?**do you have to do something with that or you just multiplying? its not working for me**excuze m**- Guest

## Re: 17.1 Maple Help

you dont have to convert k it doesnt mean anything... for 2 and 3 one of them you have to convert from mA and the other you don't have to... just play around with it alittle.

**kibakun**- Guest

## Re: 17.1 Maple Help

I'd just like to give what I believe is a helpful tip, especially for questions like

Besides remembering Ohm's Law as V=IR (this way I pronounce it out:

When you need to find the part you are looking for, just cover the letter and read out the new equation.

For instance to find Voltage

Same goes for the current

There are also a few for calculating with Power and Energy, if it's ever needed.

Hope that helps!

**Question 2**.Besides remembering Ohm's Law as V=IR (this way I pronounce it out:

*Vurr*), there's a handy little chart to remember the equation and help you find what you are looking for.When you need to find the part you are looking for, just cover the letter and read out the new equation.

For instance to find Voltage

**V**. Block out the**V**and you have the equation to figure it out which is now*I*R*Same goes for the current

**I**just place your finger over the**I**in the chart and you then have*V/R*There are also a few for calculating with Power and Energy, if it's ever needed.

*The formula for Energy being the same as for Voltage*.**E=I*R**. Power is**P=I**^{2}*RHope that helps!

**Guest01**- Posts : 133

Join date : 2008-09-19

## 17.1 #4

can somebody post a detailed way to do number 4 i just can't seem to get it

thanks!

thanks!

**frustrat**- Guest

## Re: 17.1 Maple Help

yo i still cant get #2 for some reason. I took my mA and divided by 1000 which made it a decimal. Then i did my resistance/amps and i get another decimal but its still not working. what am i doing wrong?

**pleaseee**- Guest

## #2

i'm not getting this either, i converted the mA to A by dividing by 100 then multiplied that with given kI. (tried converting kI to I as well by either multiplying by 1000 or dividing by)

i know the answer is negative though

i know the answer is negative though

**:)**- Guest

## #4

for number 4:

A 356.8 mA current flows through a 52.89 cm long wire with a 0.5 V potential difference across it. The wire is cylindrically shaped and has a radius of with 0.827 mm. What is the resistivity of the wire material (see sheet 13,16) ? Indicate with a positive (negative) sign whether the resistivity depends (does not depend) on the cross sectional shape of the wire.

use p=RA/L

p= resistivity of material

R= resistance

A= area

L= length

R=V/I so .5V/.3568A = 1.40135 ohm

A=pi*r^2 = pi(.000827^2)= 2.149*10^-6

then just plug everything in:

p=RA/L

p= (1.40135(2.149*10^-6))/.5289

p=-5.69389*10^6

A 356.8 mA current flows through a 52.89 cm long wire with a 0.5 V potential difference across it. The wire is cylindrically shaped and has a radius of with 0.827 mm. What is the resistivity of the wire material (see sheet 13,16) ? Indicate with a positive (negative) sign whether the resistivity depends (does not depend) on the cross sectional shape of the wire.

use p=RA/L

p= resistivity of material

R= resistance

A= area

L= length

R=V/I so .5V/.3568A = 1.40135 ohm

A=pi*r^2 = pi(.000827^2)= 2.149*10^-6

then just plug everything in:

p=RA/L

p= (1.40135(2.149*10^-6))/.5289

p=-5.69389*10^6

**guest768**- Guest

## #2&3

V=R*I

R=4.212

I=221.4mA

answer is neg 932.537 do not convert

I just got #3

r=(E-V_ab)/I

E=2.9

V_ab=1.817

I=197.7/1000

So....r=(2.9-1.87)/.1977

answer +5.478

hope this helps

PS One BIG fat raspberry for the joke about using this site is considered cheating

R=4.212

I=221.4mA

answer is neg 932.537 do not convert

I just got #3

r=(E-V_ab)/I

E=2.9

V_ab=1.817

I=197.7/1000

So....r=(2.9-1.87)/.1977

answer +5.478

hope this helps

PS One BIG fat raspberry for the joke about using this site is considered cheating

**super mo**- Guest

## Re: 17.1 Maple Help

so basically for question 3

subtract the two voltages given and divide it by the current thats given that u converted (meaning mA to A by dividing by 1000)

answer is positive

subtract the two voltages given and divide it by the current thats given that u converted (meaning mA to A by dividing by 1000)

answer is positive

**guest1**- Guest

## questions

Dude at least try the questions before you come to the blog for help. Some of these are so easy it takes like 5 min to work around.

**kibakun**- Guest

## Question 1

A current of 2.601 A flows through a conducting wire. How much charge passes through it in 3.151 hours (see sheet 2,4,14) ? Indicate with a positive (negative) sign whether the coventional direction of the current is in the (opposite to the) direction of the moving electrons.

How do i do this? i know it maybe easy for most people, but i can't seem to understand it. I tried using the equation and no good. I also looked at the cd and i am still not getting it. You have to convert hours to seconds right?

How do i do this? i know it maybe easy for most people, but i can't seem to understand it. I tried using the equation and no good. I also looked at the cd and i am still not getting it. You have to convert hours to seconds right?

**Guest911**- Guest

## Re: 17.1 Maple Help

#1 is simply a rearrangement of the formula I = q/t to get q, make sure you convert hours to seconds.

Does anyone know why we convert the mA to A in #3 but not #2???

Does anyone know why we convert the mA to A in #3 but not #2???

**J**- Guest

## Question 1

for question 1 what i did was i took my 2.101 A divided that by 3.151 hours well i converted to seconds....so it came to be 11343.6 seconds...so i did 2.101/11343.6 and it gives me the wrong answer still

**Guest091**- Guest

## Re: 17.1 Maple Help

miliamperes (mA) is just a thousandth of an ampere (A). This is no different then describing the relationship between milimeters and meters. Same shit as last semester.

To convert

You will need to convert your

Simple stuff, I hope this will be the last explanation of it.

For

Again shit we have done in the past fall.

Rearrange the equation to suit your needs.

To convert

**mA**into**A**divide**mA**by*1000*(or multiply by*0.001*).You will need to convert your

*Ohms*as well, from**kiliohms**to**ohms**. These conversions will bring everything to S.I. Units.Simple stuff, I hope this will be the last explanation of it.

For

**Question 1**you will need to convert hours into seconds. Multiply hours and*3600*(that is*60*60*- converting hours into minutes; the first*60*, then minutes into seconds; the second*60*)Again shit we have done in the past fall.

Rearrange the equation to suit your needs.

**Guest01**- Posts : 133

Join date : 2008-09-19

## Guest01

I don't know if this is a mis communication or if you are indeed being an asshole. It may seem super easy for you to see some of these things, but there are students in this class believe it or not, that are still trying to understand this stuff. Yes you will have lazy students here and there, but there are students who really don't understand number 2/1. So if you think students asking questions is annoying then dont freaking use the site. Otherwise stop being an asshole explaining the answers like you were some self righteous ass.

**play nic**- Guest

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