Assertion: The current density vec J at any p | vedclass

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(C) From the microscopic form of Ohm's law,$\vec J = \sigma \vec E$,where $\sigma$ is the conductivity. Since $\sigma$ is a positive scalar,the curren

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(C) From the microscopic form of Ohm's law,$\vec J = \sigma \vec E$,where $\sigma$ is the conductivity. Since $\sigma$ is a positive scalar,the current density $\vec J$ is always in the direction of the electric field $\vec E$. Thus,the Assertion is correct.Regarding the Reason,a point charge released from rest in an electrostatic field moves along the electric line of force only if the electric line of force is a straight line. If the electric lines of force are curved,the charge will not follow the path of the line of force because the velocity vector and the force vector (which is tangent to the line of force) will not remain collinear. Thus,the Reason is incorrect.

Assertion: The current density $\vec J$ at any point in an ohmic resistor is in the direction of the electric field $\vec E$ at that point.
Reason: $A$ point charge when released from rest in a region having only an electrostatic field always moves along electric lines of force.

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Assertion: The current density $\vec J$ at any point in an ohmic resistor is in the direction of the electric field $\vec E$ at that point.Reason: $A$ point charge when released from rest in a region having only an electrostatic field always moves along electric lines of force.