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

What factors affect your mental health the most right now? (select all that apply)

Lack of purpose or routine (147)
15.67%
Uncertainty around my education (154)
16.42%
Uncertainty around my future career prospects (88)
9.38%
Isolating with family (65)
6.93%
Lack of support system (eg. Teachers, counsellors) (34)
3.62%
Lack of exercise/ability to be outside (82)
8.74%
Loneliness (95)
10.13%
Financial worries (39)
4.16%
Concern about myself or my loved ones getting ill (85)
9.06%
Exposure to negative news/social media (64)
6.82%
Lack of real life entertainment (eg. cinema, gigs, restaurants) (85)
9.06%

Watched Threads

View All