AP EAMCET2009PhysicsElectrostatics
Two point charges -q and +q are located at points (0,0,-a) and (0,0, a) respectively. The electric potential at a point (0,0, z) , where z>a is
Options
- Aq a 4 ₀ z^2
- Bq 4 ₀ a
- C2 q a 4 ₀ (z^2-a^2 )
- D2 q a 4 ₀ (z^2+a^2 )
Correct answer
D. 2 q a 4 ₀ (z^2+a^2 )
Step-by-step solution
Potential at P due to (+q) charge V₁= 1 4 ₀ q (z-a) Potential at P due to (-q) charge V₂= 1 4 ₀ -q (z+a) Total potential at P due to (A B) electric dipole aligned V & =V₁+V₂ & = 1 4 ₀ q (z-a) - 1 4 ₀ q (z+a) & = q 4 ₀ (z+a-z+a) (z-a)(z+a) aligned V= 2 q a 4 ₀ (z^2-a^2 )