Question

Write an expression for the resistance of a substance

Answer 1

Answer: Resistance = resistivity ×Length /area

Explanation:

We know that ,

Resistance is directly proportional to length and inversely proportional to breadth .

Now , on removing the sign of proportionality we substitute a proportionality constant called resistivity or specific resistance . Thus the above expression is obtained .

Thanks .

Answer 2

Answer:

Explanation:

R = p×l/A where p is resistivity

L -length ; A- area.