An electric field is a region of space in which a charged body experiences electric force.

An electric field is a region around a charged particle where other charged particles experience a force. The strength and direction of the electric field at any point in space is determined by the magnitude of the charge creating the field and the distance from the charge. Electric fields are represented by field lines that point away from positive charges and toward negative charges. The electric field at a given point is calculated as the force per unit charge experienced by a test charge placed at that point.

Electric lines of force show the direction and strength of an electric field, pointing from positive to negative charges. The density of the lines indicates the field's strength, with closer lines meaning a stronger field. The properties of electric lines of force include:

1. They originate from positive charges and terminate at negative charges.
2. Electric lines of force indicate the direction of the electric field.
3. The density of the lines indicates the strength of the electric field.
4. Electric lines of force never intersect.
5. The lines are perpendicular to the surface of a conductor.
6. The lines bend according to the shape of the charge distribution.

Electric charge is a fundamental property of matter that causes it to experience a force when placed in an electromagnetic field. It is measured in coulombs (C). An electric charge can be static (at rest) or current (in motion)

Electric current (I) is the rate of flow of electric charge through a conductor, typically measured in amperes (A). Electric current is measured using an ammeter. Very small currents are detected using a galvanometer. A milliammeter measures smaller currents.

$$I = \frac{Q}{t}$$

Where;

I = Current in Ampere (A)

Q = Quantity of electricity in Coulumb (C)

t = time in seconds (s)

Example 1: A current of 100mA passes through a conductor for 2 minutes. The quantity of electricity transported is? (JAMB)

An ammeter's sensitivity refers to its ability to detect and measure small currents accurately; it depends on its internal resistance and the scale of current it is designed to measure, with higher sensitivity requiring lower internal resistance to minimize its impact on the circuit.

The accuracy of an ammeter refers to how closely its reading match the actual current flowing through a circuit. An ammeter is designed to measure electric current with a certain degree of accuracy. The accuracy of an ammeter is influenced by factors such as its design, the range it is set to, and its calibration. It is usually expressed as a percentage of the full-scale reading, for example, ±1%. This means that for a full-scale reading of 10A, the measurement error could be ±0.1A. Ensuring proper calibration and using the ammeter within its specified range can improve its accuracy.