Two wires a and b of same material. A is twice as long as B and diameter of A is twice as long as B and diameter of A is thrice that of B. If the resistance of A is 4ohm.find that of B
Answers
Given info : Two wires A and B of same material. A is twice as long as B and diameter of A is thrice that of B.
i.e., ρ₁ = ρ₂
To find : if the resistance of A is 4 ohm, the resistance of B will be...
solution : A and B are of same material. so both wires have same resistivity.
again, length of A = 2 × length of B
⇒l₁ = 2l₂
and diameter of A = 3 × diameter of B
d₁ = 3 × d₂
now we know, resistance, R = ρl/A
= ρl/πd²/4
so, R₁/R₂ = (ρ₁/ρ₂) × (l₁/l₂) × (d₂²/d₁²)
⇒4 ohm/R₂ = 1 × (2/1) × (1/3)² = 2 × 1/9 = 2/9
⇒R₂ = 18 ohm
Therefore the resistance of B is 18 ohm.
also read similar questions : a wire of resistance 4 ohm is drawn (a) to twice its original length (b) to thrice its original length . Calculate the n...
https://brainly.in/question/1281196
five years ago,A was thrice old as B , and ten years later A will be twice as old as B. what is the present age of B
https://brainly.in/question/18132360