Question

The SI unit of electric field is:
1. Cm^-2
2. Am^-1
3. Vm^-1
4. Cm^-1

Answer 1

Correct Answer - Option 3 : Vm^-1

Concept:

Electric Field

• The electric field or electric field intensity at any point is the strength of the electric field at the point.
• It is defined as the force experienced by the unit positive charge placed at that point.

\(⇒ \vec E = \frac{{\vec F}}{{{q_o}}}\)

Where F = force and qo = small test charge

• The magnitude of the electric field is

\(⇒ E = \frac{{kq}}{{{r^2}}}\)

Where K = constant called electrostatic force constant, q = sorce charge and r = distance

Electric Potential

• Electric potential is equal to the amount of work done per unit charge by an external force to move the charge q from infinity to a specific point in an electric field.

\(⇒ V=\frac{W}{q}\)

• The difference in electric potential between two points is called potential difference or voltage.
• The voltage is the electric field divided by the distance.

Explanation:

• The electric field is the force by charge or potential multiplied by the distance.
• SI Unit of electric potential is volt and SI unit of distance is meter.
• Unit of potential by distance is Volt / meter or V m ^-1.

So, the correct option is Vm-1.