JEE Main2012PhysicsUnits and DimensionsActual
The electrical resistance R of a conductor of length l and area of cross section a is given by R= l a where ' ' is the electrical resistivity. What is the dimensional formula for electrical conductivity ' ' which is reciprocal of resistivity?
Options
- A[M⁻¹ L⁻³ T^3 A^2 ]
- B[M L⁻³ T⁻³ A^2 ]
- C[M L^3 T⁻³ A⁻² ]
- D[M⁻² L^3 T^2 A⁻¹ ]
Correct answer
A. [M⁻¹ L⁻³ T^3 A^2 ]
Step-by-step solution
Dimensional formula for electrical resistivity, = [ ML ^3 ~T ⁻³ ~A ⁻² ] Dimensional formula for electrical conductivity, = 1 is [ M ⁻¹ ~L ⁻³ ~T ^3 ~A ^2 ]