Question

Two blocks P and Q of different metals having their mass in the ratio 2 : 1 are given same amount of heat. Their temperature rises by same amount. Compare their specific heat capacities.

Answer 1

Specific heat capacity,

C = `"Amount of heat supplied"/"Mass × Rise in temperature"`

C = `"Q"/("m" xx Δ"t")`

Heat input and temperature increase are identical for blocks P and Q. Assume P has a mass of 2 m and Q a mass of m, with C₁ and C₂ being their specific heat capacities, respectively.

So C₁ = `"Q"/(2"m" xx Δ"t")`

and C₂ = `"Q"/("m" xx Δ"t")`

So C₁ : C₂ = `"Q"/(2"m" xx Δ"t") ÷ "Q"/("m" xx Δ"t")`

= `"Q"/(2"m" xx Δ"t") ÷ ("m" xx Δ"t")/"Q"`

C₁ : C₂ = `1/2`

= 1 : 2