These question consist of two statements each, printed as Assertion and Reason. While answering these questions you are required to choose any one of the following four responses :
The resistivity for a substance is its resistance when it is one meteer ling and its area of crosss section is one square meter.
The SI units of resistivity are ohm metre `Omegam` and ohm centimeter `Omega cm`.

Options

A. If both the assertion and reason are true but the reason is ont the correct explanation of assertion
B. If both the assertion and reason are true but the reason is not the correct explanation of assertion.
C. If the assertion is true but reason is false.
D. If assertion is false but reason is rue

Answer

B

Explanation

We know, `prop l/A ` or `R= rho(l)/ (A)`, where proprtionality constant `rho` is called resistivity . If `l=1 m` and ` A=1 m^2` , then `R=rho`. i.e. , Resistance =Resistivity.