- Home
- Standard 11
- Physics
The density of a material $A$ is $1500 kg/m^3$ and that of another material $B$ is $2000 kg/m^3$. It is found that the heat capacity of $8$ volumes of $A$ is equal to heat capacity of $12$ volumes of $B$. The ratio of specific heats of $A$ and $B$ will be
$1 : 2$
$3 : 1$
$3 : 2$
$2 : 1$
Solution
Heat capacity is heat transferred per unit time.
Heat capacity is equal to the specific heat capacity times mass.
For $A$ mass of $8$ volumes is $8 \times 1500=12000 u n i t s$
For $B$ mass of $12$ volumes is $12 \times 2000=24000$ units
Let specific heat be $c_{A}$ and $c_{B}$ respectively for $A$ and $B .$
As heat capacity of $8$ volumes of $A$ is equal to heat capacity of $12$ volumes of $B$.
So, $c_{A} \times 12000=c_{B} \times 24000 \Rightarrow c_{A}=2 c_{B}$
So ratio is $c_{A}: c_{B}=2 c_{B}: c_{B}=2: 1$
