Three rods of identical dimensions are arranged as shown. Conductivity of the material of rods is k, area of crosssection of rods is A, length of each rod is l. Thermal resistance of the system between points A and D is, (Assume there are no losses due to radiation)

Question

Three rods of identical dimensions are arranged as shown. <img class="img-fluid question-image" alt="image" src="https://cdn.tardigrade.in/img/question/physics/ddb5649773cb6340e020d30aaeba4468-.png" /> Conductivity of the material of rods is k, area of crosssection of rods is A, length of each rod is l. Thermal resistance of the system between points A and D is, (Assume there are no losses due to radiation) (A) (3 l/k A) (B) (l/3 k A ) (C) (5 l/2 k A) (D) (3 l/2 k A)

Tardigrade Admin · Accepted Answer

Re f f=(5 R/2) Here R =(ℓ/ KA ) <img class="img-fluid question-image" alt="image" src="https://cdn.tardigrade.in/img/question/physics/665cd05778e3c9beadd286a983458725-.png" />

Q. Three rods of identical dimensions are arranged as shown.

Conductivity of the material of rods is $k$ , area of crosssection of rods is $A$ , length of each rod is $l$ . Thermal resistance of the system between points $A$ and $D$ is, (Assume there are no losses due to radiation)

$\frac{3 l}{k A}$

$\frac{l}{3 k A}$

$\frac{5 l}{2 k A}$

$\frac{3 l}{2 k A}$

$R_{e ff} = \frac{5 R}{2}$
Here $R = \frac{ℓ}{K A}$

Q. Three rods of identical dimensions are arranged as shown. Conductivity of the material of rods is k, area of crosssection of rods is A, length of each rod is l. Thermal resistance of the system between points A and D is, (Assume there are no losses due to radiation)

kA3l​

3kAl​

2kA5l​

2kA3l​