Concepts Of Physics MCQ Edition [Volume 2]PhysicsElectric Field and Potential
An electric field E = ( i 20 + j 30) N C ⁻¹ exists in a region of space. Assuming the potential at the origin is taken to be zero, determine the potential at the point (2 m , 2 m ) .
Options
- A-20 V
- B-100 V
- C-50 V
- D100 V
Correct answer
B. -100 V
Step-by-step solution
The relationship between electric potential and a uniform electric field is given by: V - V₀ = - E r Given the electric field E = 20 i + 30 j N C ⁻¹ and the position vector of the point r = 2 i + 2 j m . Since the potential at the origin is V₀ = 0 , the potential at the point (2, 2) is: V = -(20 i + 30 j ) (2 i + 2 j ) V = -(20 2 + 30 2) V = -(40 + 60) = -100 V