Author Topic: Edexcel Unit 6b (6PH08) PRACTICALS  (Read 7638 times)

Offline park

  • Newbie
  • *
  • Posts: 30
  • Reputation: 52
Re: Edexcel Unit 6b (6PH08) PRACTICALS
« Reply #15 on: May 17, 2010, 08:20:00 am »
thanks tq

Offline student

  • SF Immigrant
  • **
  • Posts: 78
  • Reputation: 60
  • Gender: Male
Re: Edexcel Unit 6b (6PH08) PRACTICALS
« Reply #16 on: May 17, 2010, 05:35:24 pm »
Sorry, but I got confused here..
Bold text inside the quote was written by me.
...

eg. A voltmeter might read: 1.25v +/-0.01v. (I guess here is a mistake, because the rest assumes it's +/-0.1v) This implies voltage between 1.24 and 1.26

Actual uncertainty therefore would be:
1mm for the rule
0.1 for the voltmeter (not 0.01?)
0.01mm for the micrometer
This can also be written as % uncertainty using the following formula:

...

Examples:
1. Finding R using a voltmeter and an ammeter if the reading on the voltmeter is 2.45v and the ammeter is 0.96A:

V=2.54 +/-0.01v
% error = 0.01/2.54*100 = 4% (not 0.3937...~0.4?)

I= 0.96A +/-A
0.01/0.96*100= 1%

combined error: 4% (0.4%)+1%= 5% (1.4% ~1%)

r=v/i

2.54/0.96 =2.56 +/- 5% (not 5%) ohms

Thanks for notes by the way! ;)
« Last Edit: May 17, 2010, 05:39:45 pm by student »

Offline T.Q

  • SF Master
  • ******
  • Posts: 1557
  • Reputation: 5081
  • Gender: Male
Re: Edexcel Unit 6b (6PH08) PRACTICALS
« Reply #17 on: May 17, 2010, 09:25:14 pm »
added *Physics Guidance notes on experimental work edexcel new spec AS/A2*

check first post
No Matter What Happens In Life , Just Don't Lose Hope :)

Offline angelofhope

  • Newbie
  • *
  • Posts: 4
  • Reputation: 14
Re: Edexcel Unit 6b (6PH08) PRACTICALS
« Reply #18 on: May 16, 2011, 09:23:41 am »
Thanks  for those notes T.Q.. m sure that wud very helpfull for those of us who are doing dat paper  :D