Respuesta :
Answer:
Explanation:
24 - gauge wire , diameter = .51 mm .
Resistivity of copper ρ = 1.72 x 10⁻⁸ ohm-m
R = ρ l / s
1.72x 10⁻⁸ / [3.14 x( .51/2)² x 10⁻⁶ ]
= 8.42 x 10⁻² ohm
= .084 ohm
B ) Current required through this wire
= 12 / .084 A
= 142.85 A
C )
Let required length be l
resistance = .084 l
2 = 12 / .084 l
l = 12 / (2 x .084)
= 71.42 m
Answer:
Explanation:
diameter of 24 gauge wire = 0.51 mm
diameter of 12 gauge wire = 2.05 mm
A.
length of wire, l = 1 m
diameter of wire, d = 0.51 mm
radius of wire, r = 0.51 /2 = 0.255 mm
resistivity of copper, ρ = 1.7 x 10^-8 ohm metre
The formula for the resistance of wire is given by
[tex]R=\rho \frac{l}{A}[/tex]
where, l is the length of wire and A be the area of crossection of wire
A = πr² = 3.14 x 0.255 x 10^-3 x 0.255 x 10^-3 = 2.04 x 10^-7 m²
The resistance of wire is
[tex]R=1.7\times10^{-8}\frac{1}{2.04\times 10^{-7}}[/tex]
R = 0.083 ohm
B.
R = 0.083 ohm
V = 12 V
Let the current is I.
Use ohm's law
V = I R
12 = I x 0.083
I = 144.6 A
C.
I = 2 A
V = 12 V
Area of wire, A = 2.04 x 10^-7 m²
Resistivity of wire, ρ = 1.7 x 10^-8 ohm metre
Let the length of the wire is l.
V = I R
12 = 2 x R
R = 6 ohm
[tex]6=1.7\times10^{-8}\frac{l}{2.04\times 10^{-7}}[/tex]
l = 72 m
