The resistance of a conducting wire is 10 ohms. If the length of this wire is doubled and the area of cross section is halved, then what will be the resistance of this wire
Answers
Answer:
40
Explanation:
old resistance = kL/A
newresistance = 2kL÷A/2 = 4kL/A = 40 ohm
resistance of wire will be 40Ω.
initial resistance of wire, R_i = 10Ω
let length of wire is l and cross Section area of it is a.
then , R = ρ l/a , where ρ is resistivity of material of the wire.
so, 10Ω = ρ l/a .........(1)
a/c to question,
new length of wire, l' = 2l
new cross sectional area of wire, a' = a/2.
so, R' = ρ l'/a'
= ρ (2l)/(a/2)
= ρ 4l/a
= 4 ρ l/a
from equation (1),
R' = 4R = 40Ω
hence, new resistance of wire will be 40Ω
also read similar questions: A wire of resistance 12 ohm is stretched so that its length is doubled and the area of cross section is halved. How will...
https://brainly.in/question/8222747
a wire of length L the resistance R is stretched so that its length is doubled and the area of cross section is halved h...
https://brainly.in/question/8346057