
Let length of wire be l,
Area of wire as A
For equivalent wire length =2l & area will be A
As the wires are connected in series combination, the thermal resistance
Req=R1+R2
⇒σeqA2l=σ1Al+σ1Al
⇒σeq2=σ11+σ21⇒σeq=σ1+σ22σ1σ2
JEE Main 2022 — Physics Thermodynamics
Two metallic wires of identical dimensions are connected is series. If σ1 and σ2 are the conductivities of the these wires respectively, the effective conductivity of the combination is :
Held on 29 Jul 2022 · Verified 6 Jul 2026.
σ1+σ2σ1σ2
σ1+σ22σ1σ2
2σ1σ2σ1+σ2
σ1σ2σ1+σ2
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