Question

В электронагревателе никелиновую проволоку заменили нихромовой проволокой такой же длины, причем сопротивление проволоки осталось прежним. 1.Какая проволока толще? 2.Во сколько раз различаются диаметры проволок?

Answer 1

Дано: р1( никелина) =42*10^-8 Ом *м, р2( нихрома) =110*10^-8 Ом *м. R1=R2, L1=L2 ; R1=p1L1 /S1; R2=p2L2/S2; p1L1/S1=p2L2/S2; p2/p1=S2/S1=110/42=2,62 раза площадь нихромовой больше, s2/S1 =пd2^2/4: пd1^2/4=(d2/d1)^2=2,62; d2/d1= корень из 2,62=1,62

Answer 2

Replacing Nichrome Wire with Nickel-Chromium Wire in an Electric Heater

When replacing nichrome wire with nickel-chromium wire of the same length and maintaining the resistance, we can determine the relative thickness of the wires and the ratio of their diameters.

1. Which wire is thicker? - The nichrome wire is thicker than the nickel-chromium wire.

2. By what factor do the wire diameters differ? - The diameters of the nichrome and nickel-chromium wires differ by the square root of the ratio of their resistivities.

The resistivity of nichrome is approximately 1.10 × 10^-6 ohm meter, while the resistivity of nickel-chromium is approximately 1.10 × 10^-6 ohm meter. Therefore, the ratio of their resistivities is 1:1, and the square root of this ratio is 1.

This means that the diameters of the two wires are the same.