Go Back   Physics Help Forum > Lobby > New Users

New Users New to PHF? Post up here and introduce yourself!

Like Tree1Likes
  • 1 Post By studiot
Reply
 
LinkBack Thread Tools Display Modes
Old Nov 1st 2017, 02:21 PM   #1
Junior Member
 
Join Date: Nov 2017
Posts: 1
Basic Physics circuits

I know this is probably really simple , but i just don't understand how to work out a question like the one attached.
Attached Thumbnails
Basic Physics circuits-problem.jpg  
alistaircook is offline   Reply With Quote
Old Nov 1st 2017, 08:30 PM   #2
Senior Member
 
Join Date: Apr 2017
Posts: 115
7 ... So ...0.8A leaves the battery ...0.2 A goes through the branch with the diode , so the current going through the 18 Ohm must be 0.6 A ...use V=IR to find the voltage across the 18 Ohm ....

8. ..The answer to part 1 is also the voltage across the other branch with 46 Ohm in series with the diode ...you have the current , 0.2 , and the voltage ... this will give you the total resistance in this branch (use V=IR)

9 ... now you have the resistance of the diode , and the current going through it ..

Calculate the power using P=I xI x R ....(I squared R)
oz93666 is offline   Reply With Quote
Old Nov 2nd 2017, 03:30 AM   #3
Senior Member
 
Join Date: Apr 2015
Location: Somerset, England
Posts: 684
alistair, have you studied Kirchoff's two circuit laws or just series and parallel circuits?

I assume you have Ohm's law under your belt?
topsquark likes this.
studiot is offline   Reply With Quote
Reply

  Physics Help Forum > Lobby > New Users

Tags
basic, circuits, physics



Thread Tools
Display Modes


Similar Physics Forum Discussions
Thread Thread Starter Forum Replies Last Post
Need help for some basic PHYSICS questions, immediately Nuflan General Physics 4 Aug 18th 2017 06:40 AM
Need basic help understanding liquid physics craig Thermodynamics and Fluid Mechanics 9 Oct 10th 2014 05:02 PM
Help with some Basic Word problems Ch 2 book Physics Wilder7bc Kinematics and Dynamics 14 Jan 19th 2010 10:37 PM


Facebook Twitter Google+ RSS Feed