two different wires whose specific are in the ratio 2:3 length 3:4 and radius of cross section 1:2 the ratio of their resistance is
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Answered by
3
Answer:2:1
Explanation:in question radius ratio is given
So we can find area of cross section
Answered by
5
Answer:
The specific resistance of two different wires are in the ratio, ρ₁/ρ₂ = 2:3
The length of the wires are in the ratio, l₁/l₂ = 1:2
The radius of the cross-section of the wires are in the ratio, r₁/r₂ = 1:2
By using the formula for finding the resistance of a wire,
R = ρL/A
Where
ρ = specific resistance
l = length of wire
A = cross-sectional area of wire = πr²
So we can write the above formula as,
R = ρL/πr²
⇒ R ∝ ρL/r²
Let the resistances of the wires be “R₁” & “R₂”.
Thus,
The ratio of the resistance of wires is,
= R₁/R₂
= [ρ₁l₁/r₁²] / [ρ₂l₂/r₂²]
= [ρ₁/ρ₂] * [l₁/l₂] * [r₂/r₁]²
= [2/3] * [3/4] * [2/1]²
= 2
= 2:1
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