JEE Main 2025 · 2 April · evening · Single correct · +4 / −1
Match List - I with List - II.
List - I, List - II; (A), Heat capacity of body, (I) J kg⁻¹; (B), Specific heat capacity of body, (II) J K⁻¹; (C), Latent heat, (III) J kg⁻¹ K⁻¹; (D), Thermal conductivity, (IV) J m⁻¹ K⁻¹ s⁻¹
Choose the correct answer from the options given below :
- (a) (A)-(IV), (B)-(III), (C)-(II), (D)-(I)
- (b) (A)-(III), (B)-(I), (C)-(II), (D)-(IV)
- (c) (A)-(III), (B)-(IV), (C)-(I), (D)-(II)
- (d) (A)-(II), (B)-(III), (C)-(I), (D)-(IV)
Answer and solution
Answer (d) (A)-(II), (B)-(III), (C)-(I), (D)-(IV)
Solution
Physics sir · 3 steps
Write the defining equation for each quantity, make it the subject, and the unit falls out.
- Start from definitions. Each quantity is defined by an equation for heat Q, which is in joules. Rearrange that equation for the quantity and put in the units of everything else.
Quantity Defining equation Rearranged Unit (A) Heat capacity Q = C Δ T C = Q/(Δ T) J K⁻¹, (II) (B) Specific heat capacity Q = mc Δ T c = Q/(m Δ T) J kg⁻¹ K⁻¹, (III) (C) Latent heat Q = mL L = Q/m J kg⁻¹, (I) (D) Thermal conductivity Q/t = (kA Δ T)/l k = (Q l)/(t A Δ T) J m⁻¹ K⁻¹ s⁻¹, (IV) - Conductivity units. For k: (J × m)/(s × m² × K) = J m⁻¹ K⁻¹ s⁻¹. One metre from the thickness l cancels one from the area A.
- So. The matching is (A)-(II), (B)-(III), (C)-(I), (D)-(IV), which is option (d).
The idea to keep. The word "specific" in thermal physics means "per kilogram". Heat capacity is for the whole body, so it has no kg⁻¹. Specific heat capacity is per kilogram, so it does.
Answer from the NTA final answer key. Solution by PrepWiser.