Answer:
The equation is: [tex]R = \frac{L}{A}[/tex]
Step-by-step explanation:
The resistance, R (in ohms), of a wire varies directly with the length, L (in cm), of the wire, and inversely with the cross-sectional area, A (in cm2).
This means that we want to find an equation for R, which is a fraction.
Since it varies directly with the length L, L is the numerator.
Since it varies inversely with the cross-sectional area, A is the denominator.
So the equation is:
[tex]R = \frac{L}{A}[/tex]
Answer:
R ∝ L/ A
R = K L/ A
0.025= 500K/0.126
the constant, K=6.3 X 10^-6
Step-by-step explanation:
Step 1
The resistance, R (in ohms), of a wire varies directly with the length, L (in cm), of the wire, and inversely with the cross-sectional
area, A (in cm2) is written mathematically as
R ∝ L/ A
Introducing the constant of proportionality,K, we have
R = K L/ A
So given that s 500 cm piece of wire with a radius of 0.2 cm has a resistance of 0.025 ohm.
We would First find area , since radius was given
Area = πr²
= 3.142 x 0.2²= 0.126cm²
Step 2
With our equation , R = K L/ A, puting all the necessary variables, we have
R = K L/ A
0.025= 500K/0.126
Solving for K
0.025= 500K/ 0.126
(0.025 X 0.126)/500 = K
K=6.3 X 10^-6
