HELP DC CIRCUITS question RESISTIVITY Watch

MrToodles4
Badges: 10
Rep:
?
#1
Report Thread starter 2 years ago
#1
It's just this last bit of a question - i think the markscheme is wrong but I need to make sure.

It is question 9B:

http://pmt.physicsandmathstutor.com/...20Circuits.pdf

Basically the markscheme uses 3.5*10^-5 for the resistivity when the question said the "resistivity of the resistive material = 5.0*10^-6 ohmmeters."

Link to markscheme:
http://pmt.physicsandmathstutor.com/...cuits%20MS.pdf

Is this incorrect? The answer they got is 0.6mm where i get 1mm.
Could someone tell me what they get? many thanks.
0
reply
uberteknik
  • Study Helper
Badges: 21
Rep:
?
#2
Report 2 years ago
#2
(Original post by MrToodles4)
It's just this last bit of a question - i think the markscheme is wrong but I need to make sure.

It is question 9B:

http://pmt.physicsandmathstutor.com/...20Circuits.pdf

Basically the markscheme uses 3.5*10^-5 for the resistivity when the question said the "resistivity of the resistive material = 5.0*10^-6 ohmmeters."

Link to markscheme:
http://pmt.physicsandmathstutor.com/...cuits%20MS.pdf

Is this incorrect? The answer they got is 0.6mm where i get 1mm.
Could someone tell me what they get? many thanks.
Yes. Looks like an error in the mark scheme.

R = \frac{\rho L}{wt}

t = \frac{\rho L}{wR}

t = \frac{5 \mathrm {x}10^{-5}\ \mathrm  {x}\ 0.8}{2.5 \mathrm {x}10^{-3}\ \mathrm {x}\ 16}

t = \frac{4 \mathrm {x}10^{-5}}{0.04}

t = 1 \mathrm {x}10^{-3} \mathrm {m} = 1 \mathrm {mm}
1
reply
MrToodles4
Badges: 10
Rep:
?
#3
Report Thread starter 2 years ago
#3
(Original post by uberteknik)
Yes. Looks like an error in the mark scheme.

R = \frac{\rho L}{wt}

t = \frac{\rho L}{wR}

t = \frac{5 \mathrm {x}10^{-5}\ \mathrm  {x}\ 0.8}{2.5 \mathrm {x}10^{-3}\ \mathrm {x}\ 16}

t = \frac{4 \mathrm {x}10^{-5}}{0.04}

t = 1 \mathrm {x}10^{-3} \mathrm {m} = 1 \mathrm {mm}
Thank you
1
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Back
to top
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

University open days

  • Bournemouth University
    Undergraduate Open Day Undergraduate
    Wed, 19 Feb '20
  • Buckinghamshire New University
    Postgraduate and professional courses Postgraduate
    Wed, 19 Feb '20
  • University of Warwick
    Warwick Business School Postgraduate
    Thu, 20 Feb '20

Have you ever accessed mental health support services at University?

Yes (46)
24.73%
No, but I have thought about it (50)
26.88%
No (90)
48.39%

Watched Threads

View All