If both the resistance and the inductance in an LR AC series circuit are doubled the new impedance will be
Options
(a) halved
(b) fourfold
(c) doubled
(d) quadrupled
Correct Answer:
doubled
Explanation:
For L-R circuit, Z = √(R² + Xʟ²)
Z₁ = √(R₁² + Xʟ₂²)
Z₂ = √(R₂² + Xʟ₂²)
Given, R₂ = 2R and Xʟ₂ = 2Xʟ
Then, Z₂ = √[(2R)² + (2Xʟ)²] = 2 Z₁