A metallic object cools from temperature T₁ to T₂. Its specific heat varies as C=a+bT², where T is in kelvin. The change in specific entropy of the object during cooling is:
Options

Question

A metallic object cools from temperature T₁ to T₂. Its specific heat varies as C=a+bT², where T is in kelvin. The change in specific entropy of the object during cooling is:

G1 Physics · Accepted Answer

For a reversible temperature change, dS=C dT/T. Here C=a+bT², so ΔS=∫ from T₁ to T₂ [a/T+bT]dT =a ln(T₂/T₁)+(b/2)(T₂²−T₁²). Option A.