Results 1 to 3 of 3

Math Help - circuit resistance

  1. #1
    Member
    Joined
    Nov 2009
    Posts
    94

    circuit resistance

    1. The problem statement, all variables and given/known data
    hi
    i am wondering if this is correct. this is the question;
    Three cells, each of e.m.f. 15 V and internal resistance 050 Ω, are connected in series to
    make a battery of e.m.f. 45V. The battery is connected to a resistor, R, of resistance 60 Ω.

    2. Relevant equations
    V= i/R

    3. The attempt at a solution
    TOTAL VOLTAGE = 4.5V
    TOTAL RESISTANCE = 6.5 OHMS
    but the answer states the total resistnace is 7.5 ohms.
    can someone kindly explain how?
    thanks
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Senior Member BAdhi's Avatar
    Joined
    Oct 2010
    From
    Gampaha, Sri Lanka
    Posts
    252
    Thanks
    6
    when batteries are connected in series the total internal resistance of the batteries can be taken as 3(0.5) so with that and the additional 6, you'll get 7.5
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Member
    Joined
    Nov 2009
    Posts
    94
    Quote Originally Posted by BAdhi View Post
    when batteries are connected in series the total internal resistance of the batteries can be taken as 3(0.5) so with that and the additional 6, you'll get 7.5
    apologies for any replies. in crazy exam mode. 8 papers in january! thanks for the hints. its understandable now.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Circuit Analysis - Redrawing Circuit
    Posted in the Math Topics Forum
    Replies: 0
    Last Post: September 13th 2011, 06:20 PM
  2. air resistance
    Posted in the Math Topics Forum
    Replies: 1
    Last Post: September 28th 2010, 01:57 AM
  3. resistance of wires
    Posted in the Math Topics Forum
    Replies: 5
    Last Post: January 7th 2009, 03:13 AM
  4. electrical resistance
    Posted in the Math Topics Forum
    Replies: 2
    Last Post: December 13th 2008, 10:40 PM
  5. Resistance at certain lux
    Posted in the Pre-Calculus Forum
    Replies: 14
    Last Post: October 12th 2007, 12:51 PM

Search Tags


/mathhelpforum @mathhelpforum