Question

What is the resistance of a 2.0 m copper wire ( p= 1.7 10∧-8 mΩ-m) that has a cross-sectional area of

2.08 x 10∧-6 m∧2?

A. 1.6 10∧-2Ω
B. 6.1 10∧1 Ω
C. 4.1 10∧-3 Ω
D. 2.4 10∧2 Ω

Answer 1

Ans: the correct option is (a)


`R = p(l)/(A)`

where, R is the resistance.
p is the resisitvity (p= 1.7 10∧-8 mΩ-m)
A is the Area (2.08 x 10∧-6 m∧2)
L is the length = 2.0 m

⇒
`R =1.7*10^(-8)( (2)/(2.8*10^(-6)) )`
⇒ R = 1.6 *10^{-2} ohm

Answer 2

Answer:
Resistance = 1.634 * 10^-2 ohm

Step-by-step explanation:
The resistance can be calculated using the following rule:
Resistance = (ρL) / A
where:
ρ is the resistivity = 1.7 * 10^-8
L is the length of the wire = 2 m
A is the cross sectional area of the wire = 2.08 * 10^-6 m²

Substitute with the givens in the above equation to get the resistance as follows:
Resistance = (1.7 * 10^-8 * 2) / (2.08 * 10^-6)
Resistance = 1.634 * 10^-2 ohm

Hope this helps :)