HELP DC CIRCUITS question RESISTIVITY

Watch this thread
MrToodles4
Badges: 10
Rep:
? You'll earn badges for being active around the site. Rep gems come when your posts are rated by other community members.
#1
Report Thread starter 5 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
Badges: 21
Rep:
? You'll earn badges for being active around the site. Rep gems come when your posts are rated by other community members.
#2
Report 5 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:
? You'll earn badges for being active around the site. Rep gems come when your posts are rated by other community members.
#3
Report Thread starter 5 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

Do you know what you'll do if you don't get the grades you're hoping for?

Find something else in clearing (40)
28.99%
Take a gap year (22)
15.94%
Resit my exams (37)
26.81%
Look for alternate pathways to the career I want (18)
13.04%
I don't know yet (15)
10.87%
Something else (tell us in the thread) (6)
4.35%

Watched Threads

View All