Question

Assertion(A):
Electric field is always normal to equipotential surfaces and along the
direction of decreasing order of potential
Reason(R):
Negative gradient of electric potential is electric field.​

Answer 1

Answer:

Assertion and Reason both are correct but Reason is not the correct explanation of Assertion

Explanation:

There is no potential gradient along any direction parallel to the surface, and no electric field is parallel with the surface, This means electric field are always at right angle to the equipotential surface.

As we know electric field lines show us the electric field direction. ... So electric field points out the direction in which potential energy function is decreasing so it's the negative gradient vector of the potential energy function.

Answer 2

Assertion(A): Electric field is always normal to equipotential surfaces and along the

direction of decreasing order of potential.

Reason(R): Negative gradient of electric potential is electric field.

Assertion and Reason are true , but reason is not the correct explanation.

But why?

• Direction of electric field intensity is always perpendicular to the equipotential surfaces. The field intensity is also directed along the direction of decreasing electric potential. So, Assertion is true.

• $\boxed{E = -\dfrac{\partial V}{\partial r}}$. So, reason is also true.

• However, this reason is not the adequate explanation for the perpendicular orientation of field intensity with respect to equipotential surfaces.

• But the negative sign shows that field intensity directs along decreasing potential values.

Hope It Helps.