Question

Dimensions of a block are 1cm1cm100cm. If specific resistance of its material is
3 107ohmm, then the resistance between the opposite rectangular faces is

Answer 1

Answer:

The resistance between the opposite rectangular faces is $\bold{3 \times 10^{11}}$ ohms.

Explanation:

We have dimension as 1cm´1cm´100cm

Specific resistance of material= $3 \times 10^{7}$ ohm

We have to find the resistance between the opposite rectangular faces

Length L= 100 cm=1m

Area $=1 \mathrm{cm}^{2}=10^{-4} \mathrm{m}^{2}$

Resistance ρ=$3 \times 10^{7}$  ohm/m

We know that resistance = $\frac{\rho L}{A}$

By substituting the values we have

=$\left(3 \times 10^{7} \times 1\right) / 10^{-4}$

By simplification of above expression  

We get the solution as  

$3 \times 10^{11}$ ohm

Hence resistance of the opposite faces = $3 \times 10^{11}$

Answer 2

Answer:

           3×10 power(7)Ω

Explanation:

         opposite rectangular faces

         l=1cm=10^-2m  and  a=1cm*100cm=10^-2m*1m=10^-2m²

         R=p(l/a)

         R= [3×10 power(7)]×(10^-2/10^-2)

        ∴ R=3×10 power(7) Ω