NEETPhysicsUnits and Dimensions
What is the dimensional formula of electrical mobility?
Options
- A[ MLT ⁻³ A ⁻¹ ]
- B[ M ⁻¹ L ² T ⁻² A ]
- C[ M ⁻¹ L ⁰ TA ]
- D[ M ⁻¹ L ⁰ T ² A ]
Correct answer
D. [ M ⁻¹ L ⁰ T ² A ]
Step-by-step solution
Electrical mobility ( ) is defined as the magnitude of drift velocity ( v_d ) per unit electric field ( E ). = v_d E The dimensional formula of drift velocity v_d is [ LT ⁻¹] . Electric field E = F q The dimensional formula of force F is [ MLT ⁻²] and that of charge q is [ AT ] . Thus, [E] = [ MLT ⁻²] [ AT ] = [ MLT ⁻³ A ⁻¹] . Therefore, the dimensional formula of electrical mobility is: [ ] = [ LT ⁻¹] [ MLT ⁻³ A ⁻¹] = [ M ⁻¹ L ⁰ T ² A ] . Answer: [ M ⁻¹ L ⁰ T ² A ]