Two identical square rods of metal are welded | vedclass

Name: PDF Generator App | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(a) $\frac{Q}{t} = \frac{{KA\,\Delta 	heta }}{l}$$ = \frac{{\Delta 	heta }}{{(l/KA)}} = \frac{{\Delta 	heta }}{R}$ ( $R =$  Thermal resistance

Vedclass · Accepted Answer

$1$

Vedclass · Answer

(a) $\frac{Q}{t} = \frac{{KA\,\Delta 	heta }}{l}$$ = \frac{{\Delta 	heta }}{{(l/KA)}} = \frac{{\Delta 	heta }}{R}$ ( $R =$  Thermal resistance)

==> $t \propto R$ ( $Q$ and $\Delta 	heta $ are same)

==> $\frac{{{t_P}}}{{{t_S}}} = \frac{{{R_P}}}{{{R_S}}} = \frac{{R/2}}{{2R}} = \frac{1}{4}$

==>${t_P} = \frac{{{t_S}}}{4} = \frac{4}{4} = 1\min .$

(Series resistance ${R_S} = {R_1} + {R_2}$ and parallel resistance ${R_P} = \frac{{{R_1}{R_2}}}{{{R_1} + {R_2}}}$)

Two identical square rods of metal are welded end to end as shown in figure $(i)$ , $20$ calories of heat flows through it in $4$ minutes. If the rods are welded as shown in figure $(ii)$, the same amount of heat will flow through the rods in ....... $\min.$

Similar Questions

Five rods of same dimensions are arranged as shown in the figure. They have thermal conductivities $K1, K2, K3, K4$ and $K5$ . When points $A$ and $B$ are maintained at different temperatures, no heat flows through the central rod if

Select correct statement related to heat .......

Woollen clothes are used in winter season because woolen clothes

According to the experiment of Ingen Hausz the relation between the thermal conductivity of a metal rod is $ K$ and the length of the rod whenever the wax melts is

The two opposite faces of a cubical piece of iron (thermal conductivity $= 0.2\, CGS$ units) are at ${100^o}C$ and ${0^o}C$ in ice. If the area of a surface is $4c{m^2}$, then the mass of ice melted in $10$ minutes will be ...... $gm$