A metal rod of length 10 cm and a rectangula | vedclass

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

Question

(B) The resistance $R$ of a conductor is given by the formula $R = \rho \frac{l}{A}$,where $\rho$ is the resistivity,$l$ is the length of the conducto

Vedclass · Accepted Answer

Maximum when the battery is connected across $1 \ cm 	imes 0.5 \ cm$ faces.

Vedclass · Answer

(B) The resistance $R$ of a conductor is given by the formula $R = ho \frac{l}{A}$,where $ho$ is the resistivity,$l$ is the length of the conductor in the direction of current flow,and $A$ is the cross-sectional area perpendicular to the current flow.To maximize the resistance $R$,we need to maximize the ratio $\frac{l}{A}$. This means we need the largest possible length $l$ and the smallest possible cross-sectional area $A$.The dimensions of the rod are $10 \ cm$,$1 \ cm$,and $0.5 \ cm$.If the battery is connected across the $1 \ cm 	imes 0.5 \ cm$ faces,the current flows through the length $l = 10 \ cm$. The area of cross-section is $A = 1 \ cm 	imes 0.5 \ cm = 0.5 \ cm^2$.In this case,the ratio $\frac{l}{A} = \frac{10}{0.5} = 20 \ cm^{-1}$.Comparing this with other configurations,this configuration yields the maximum value for the ratio $\frac{l}{A}$,hence the resistance is maximum.

$A$ metal rod of length $10 \ cm$ and a rectangular cross-section of $1 \ cm \times 0.5 \ cm$ is connected to a battery across opposite faces. The resistance will be . . . . . . .

Similar Questions

What is conductance? Write its unit.

In an experiment,the resistance of a material is plotted as a function of temperature. As shown in the figure,the plot of $\ln R(T)$ versus $1/T^2$ is a straight line. One may conclude that:

What is the resistance of a cubic block of length $50 \, cm$ having a resistivity of $50 \times 10^{-8} \, \Omega m$?

Two metal wires of identical dimensions are connected in series. If $\sigma_1$ and $\sigma_2$ are the conductivities of the metal wires respectively,the effective conductivity of the combination is

Dimensions of a block are $1 \, cm \times 1 \, cm \times 100 \, cm$. If the specific resistance of its material is $3 \times 10^{-7} \, \Omega \cdot m$,the resistance between the square faces is:

Vedclass Test Series

Exam Paper Generator

Online Exam Module