engineering recuitment BHEL Engineer Trainee Mock Test 2025 Electromagnetic Theory Maxwell's Equations
वह समीकरण क्या है जो पृथक चुंबकीय ध्रुव के गैर-अस्तित्व को बताता है?
1
∇ ⋅ D = ρ
2
∇ ⋅ B = 0
3
\(\nabla \cdot J = - \frac{{\partial \rho }}{{\partial t}}\)
4
∇ × H = J