Two cylindrical rods of same cross-section area and same length are connected in series to an ideal cell as shown. The resistivity of the left rod is ρ and that of the right rod is 2 ρ . Then, the variation of potential at any point P at a distance x from the left end of the combined system is most appropriately shown in which of the plots?

Question

Two cylindrical rods of same cross-section area and same length are connected in series to an ideal cell as shown. The resistivity of the left rod is ρ and that of the right rod is 2 ρ . Then, the variation of potential at any point P at a distance x from the left end of the combined system is most appropriately shown in which of the plots? Question

(A)

(B)

(C)

(D)

Tardigrade Admin · Accepted Answer

From relation, textE = ρ textJ , the magnitude of the electric field is greater in the right rod as compared to the left rod. Therefore the magnitude of the potential gradient in the right rod is greater. (Remember that potential is continuous). Therefore the variation is shown by the following figure. <img class="img-fluid question-image" alt="Solution" src="https://cdn.tardigrade.in/q/nta/p-ae94johnve7i.png" />

From relation, E=ρJ , the magnitude of the electric field is greater in the right rod as compared to the left rod. Therefore the magnitude of the potential gradient in the right rod is greater. (Remember that potential is continuous). Therefore the variation is shown by the following figure.

From relation, $E = ρ J$ , the magnitude of the electric field is greater in the right rod as compared to the left rod. Therefore the magnitude of the potential gradient in the right rod is greater. (Remember that potential is continuous).
Therefore the variation is shown by the following figure.