Correct Answer - Option 3 : Type of material
CONCEPT:
-
Resistance (R): Resistance is the property of a material by virtue of which it opposes the flow of charge through it.
- It can also be defined as the ratio of the potential difference applied across the conductor to the current flowing through it.
\(\Rightarrow R = \frac{V}{I}\)
- Si unit of Resistance is the ohm (ω)
-
Resistivity or Specific resistance (ρ): It is the measure of the ability of the material to oppose the flow of current.
- Resistivity is the property of material i.e. it has different constant values of different material
- SI unit of resistivity is ohm- meter
- Relation between resistance and resistivity is given as
\(⇒R = \frac{ρ \times l}{A}\)
Where R is resistance, l is the length of the conductor, A is an area of cross-section of conductor, p is the resistivity of the material
EXPLAINATION:
- From the above discussion, it is seen that resistivity is constant for different materials i.e every material posses its own resistivity, due to which resistivity is independent of length and area.
- It is material property therefore resistivity depends on the type of material. Hence, the correct option is (3)
