GATE 2021 BM – Question 53
The shown ladder has R₁=2 Ω,R₂=1 Ω,L₁=2 H,L₂=0.5 H, with output across R₂. Which descriptions apply?
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Show answer and explanation
Correct answer: (B) Second-order low-pass filter; (D) Overdamped system
Explanation
Nodal reduction gives H(s)=R₁R₂/[L₁L₂s²+(L₁R₁+L₁R₂+L₂R₁)s+R₁R₂]=2/(s²+7s+2). DC gain is one and high-frequency gain tends to zero, giving second-order low-pass B. The pole discriminant 49−8=41 is positive, so poles are real negative and the system is overdamped, D.