Hey there! Sign in to join this conversationNew here? Join for free
    • Thread Starter
    Offline

    0
    ReputationRep:
    Hello, I'm stuck on these questions

    Q1) What length of copper wire of diameter 0.38mm would be need to limit the current in it to 0.5A when connected to a 2V battery?

    A=\pi (0.19 \times10^{-3})^2

    A=1.13 \times 10^{-7}

    V=IR

    2=0.5R

    R=4

    R=\frac{pL}{A}

    4=\frac{1.7\times10^{-8}\times L}{1.13\times 10^{-7}}

    \frac{4(1.13 \times10^{-7})}{1.7 \times10^{-8}}=L, L=26.7

    Is that correct?

    Q2)A 0.28mm diameter copper wire, 15.0m long, is connected to a 3.0V battery. Find its resistance and the current flowing.

    A=\pi(0.14 \times10^{-3})^2

    A=6.18 \times 10^{-8}

    ...What do I do next to answer the question?

    Thanks a lot.
    Offline

    10
    Duplicate question already answered in the other thread.
 
 
 
  • 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.

  • Poll
    Has a teacher ever helped you cheat?
  • 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.

  • The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

    Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

    Write a reply...
    Reply
    Hide
    Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.