Friday, 17 May 2013

A copper wire has diameter 0.5 mm and resistivity of


Question 6:
A copper wire has diameter 0.5 mm and resistivity of 1.6 × 10−8 Ω m. What will be the length of this wire to make its resistance 10 Ω? How much does the resistance change if the diameter is doubled?
Solution:
Area of cross-section of the wire, A =π (d/2) 2
Diameter= 0.5 mm = 0.0005 m
Resistance, R = 10 Ω
We know that






length of the wire = 122.72m
If the diameter of the wire is doubled, new diameter=2×0.5=1mm=0.001m
Let new resistance be Rʹ
 


the new resistance is 2.5 Ω
 

19 comments:

  1. They have asked that how much the resistance will change, and not what will be the resistance?

    ReplyDelete
    Replies
    1. Yes..
      If the length is doubled and the diameter is reduced to half
      Will the resistance change? or be same?

      Delete
    2. After finding the resistance just substract it ....or u can't even do that

      Delete
    3. I FOUND A CLASH OF CLANS GEMS GIVEAWAY! http://myclashgems.com You can get the gems again and again! (BBLV2)

      Delete
  2. This comment has been removed by the author.

    ReplyDelete
  3. Sorry but your answere is wrong it should be 1.23m.
    Your mistake is at the square of 0.0005, it is 2.5.
    Still thanks.

    ReplyDelete
  4. Free Clash of Clans diamonds bonus http://maxclashgems.com Now you will know why some clans are so strong! (90kQj)

    ReplyDelete
  5. What will be the resistance if diameter is halved

    ReplyDelete
  6. I like to play Clash of Clans and I use http://myclashgems.com It really works! (mprBN)

    ReplyDelete
  7. This comment has been removed by the author.

    ReplyDelete
  8. Sorry my mistake the ans is correct im idiot

    ReplyDelete
  9. Supppe thank u for this ways u to help us

    ReplyDelete