Two vessels of different materials are similar in size in every respect. same quantity of ice filled

English

Gujarati

Hindi

10-2.Transmission of Heat

medium

Two vessels of different materials are similar in size in every respect. The same quantity of ice filled in them gets melted in $20$ minutes and $40$ minutes respectively. The ratio of thermal conductivities of the materials is

A

$5:6$

B

$6:5$

C

$3:1$

D

$2:1$

Solution

(d) $\frac{Q}{t} = \frac{{KA({\theta _1} – {\theta _2})}}{l}$ ==> $\frac{{mL}}{t} = \frac{{KA({\theta _1} – {\theta _2})}}{l}$

==> $K \propto \frac{1}{t}$ ( $\because$ remaining quantities are same)

==> $\frac{{{K_1}}}{{{K_2}}} = \frac{{{t_2}}}{{{t_1}}}$$ = \frac{{40}}{{20}} = \frac{2}{1}$.

Standard 11

Physics

Share

Similar Questions

One end of a metal rod of length $1.0 m$ and area of cross section $100c{m^2}$ is maintained at ${100^o}C.$If the other end of the rod is maintained at ${0^o}C$, the quantity of heat transmitted through the rod per minute is (Coefficient of thermal conductivity of material of rod =$100W/m-K$)

medium

An ice cube of dimensions $60\,cm \times 50\,cm \times 20\,cm$ is placed in an insulation box of wall thickness $1\,cm$. The box keeping the ice cube at $0^{\circ}\,C$ of temperature is brought to a room of temperature $40^{\circ}\,C$. The rate of melting of ice is approximately. (Latent heat of fusion of ice is $3.4 \times 10^{5}\,J\,kg ^{-1}$ and thermal conducting of insulation wall is $0.05\,Wm ^{-10} C ^{-1}$ )

hard

(JEE MAIN-2022)

Two different rods $A$ and $B$ are kept as shown in figure. The ratio of thermal conductivities of $A$ and $B$ is

medium

Three rods made of the same material and having the same cross section have been joined as shown in the figure. Each rod is of the same length. The left and right ends are kept at ${0^o}C$ and ${90^o}C$ respectively. The temperature of the junction of the three rods will be …… $^oC$

medium

(IIT-2001)

Three conducting rods of same material and cross-section are shown in figure. Temperatures of$ A, D$ and $C$ are maintained at $20^o C, 90^o C$ and $0^o C$. The ratio of lengths of $BD$ and $BC$ if there is no heat flow in $AB$ is:

medium