As I mentioned elsewhere, I am trying to teach myself EE primarily using the Horowitz and Hill book "The Art of Electronics." My math is VERY rusty right now so I wind up doubting my results on some things. Case in point is Exercise 1.6. It has to do with calculating a: the power lost per foot from "P=IIR" losses (II meaning "I squared") b:the length of cable over which you will lose all 10 to the 10th power watts of power. and C: how hot the cable will get using the formula σ=6 X 10 to the minus 12thW/K to the 4th X cm squared. The parameters are 10 to the 10th power Watts at 110 volts through a 1 foot diameter pure copper cable with a resistance of 5 X 10 to the -8th Ohms/foot
To get the power loss per foot I've used the formula P = Vsquared/R and come up with the answer of 242,000,000,000 (!?) I then divide 10 to the 10th Watts by that answer and get .041322314... As far as C: is concerned I THINK I would put K on the left side and multiply the Watts time the cm squared. Is my methodology correct? or am I making fatal algebraic errors somewhere
Thanks in advance.
Dan Carter
To get the power loss per foot I've used the formula P = Vsquared/R and come up with the answer of 242,000,000,000 (!?) I then divide 10 to the 10th Watts by that answer and get .041322314... As far as C: is concerned I THINK I would put K on the left side and multiply the Watts time the cm squared. Is my methodology correct? or am I making fatal algebraic errors somewhere
Thanks in advance.
Dan Carter