Sep 30, 2007 #1 K keni4eva Newbie level 5 Joined Sep 30, 2007 Messages 10 Helped 0 Reputation 0 Reaction score 0 Trophy points 1,281 Activity points 1,345 A conductor of 0.5mm diameter wire has a resistance of 300Ω. Find the resistance of the same length of wire if its diameter were doubled.
A conductor of 0.5mm diameter wire has a resistance of 300Ω. Find the resistance of the same length of wire if its diameter were doubled.
Sep 30, 2007 #2 the_risk_master Advanced Member level 2 Joined Aug 12, 2005 Messages 660 Helped 79 Reputation 158 Reaction score 19 Trophy points 1,298 Location UE+MIT, Philippines, (14°N , 120°E ) Activity points 5,514 Re: PLS HELP R = (ρL)/A where: ρ - resistivity constant of the material L - length of the material A - cross-sectional area of the material at length since: L1 = L2 and ρ1 = ρ2 and A = (pi×D²)/4 ---- circular area thus: (R1×A1) = (R2×A2) R2 = R1 (A1/A2) R2 = R1 ( (D1)²/(D2)²) but: D2 = 2×(D1) R2 = R1 ( (D1)²/(2×D1)²) ---- D1 cancels R2 = R1 / (2²) = R1 /4 R2 = (300Ω)/4 R2 = 75Ω Very elementary!
Re: PLS HELP R = (ρL)/A where: ρ - resistivity constant of the material L - length of the material A - cross-sectional area of the material at length since: L1 = L2 and ρ1 = ρ2 and A = (pi×D²)/4 ---- circular area thus: (R1×A1) = (R2×A2) R2 = R1 (A1/A2) R2 = R1 ( (D1)²/(D2)²) but: D2 = 2×(D1) R2 = R1 ( (D1)²/(2×D1)²) ---- D1 cancels R2 = R1 / (2²) = R1 /4 R2 = (300Ω)/4 R2 = 75Ω Very elementary!
Oct 1, 2007 #3 F forkschgrad Full Member level 5 Joined Apr 6, 2007 Messages 271 Helped 18 Reputation 36 Reaction score 9 Trophy points 1,298 Location Philippines Activity points 2,363 Re: PLS HELP way to go