Electric circuits basic study include many topics which include  electric circuits component, electric circuit drawing and Kirchoff’s law, projects. Others are electric circuit simulation software, electric circuit series and parallel, and electric circuit test,

An electric circuit is a means to transport electric power from the source to the load. For electricity to do any useful work, current must flow. Electric current can flow only through conductors and to certain degree in semiconductors. However, insulators will not permit such flow.

An insulator is a material in which electron cannot move easily from one atom to another. Insulators protects against harmful effects of electricity. They have more than four electrons in the valence. Types of insulators include ceramic, glass, plastic, rubber, air, and wood etc.
Atomic structure of insulators:

Electrical conductor materials

A conductor is a material in which electron can move fairly well between atoms. Two metals of the same materials and thickness at different length have different resistance values. The two metals at same length but different thickness exhibits different resistance value. Long wire has more resistance compared to short wire. Thin wire has more resistance than thick wire. A semiconductor is a material such as silicon. Semiconductors are either conductor or insulator materials.

First, there must be a closed path or circuit for current to flow. The closed circuit contains a conductor covered with an insulator, a switch, a source of power (a battery for example) and a load. An example of a load is your appliances. Second, the circuit must have a continuous supply of electrical charges from an electric field such as a battery. Electron (electric current) flows from negative to positive, that is, electron flow.  However, in conventional current flow, electron (electric current) flows from positive to negative. Besides, in calculations, you arrived at the same answer, either you choose, electron flow or conventional current flow. But the best approach is that electron flows from negative to positive.

Electric Circuits Component

Flow of current is determined by applied voltage and resistance (or impedance) in the circuit. Keeping resistance constant, increased voltage produce more current flow; reduced voltage reduces current flow. Keeping voltage constant, increased resistance produce less current flow; reduced resistance increases current flow. You can measure current in a circuit with Ammeter and the unit of current is Ampere. A typical electric circuit controls the working of a hot air sterilizer.

Resistance

Resistance is the property of a material to oppose the movement of electron (current). All electric circuits has inherent resistance. For example, internal resistance from source and resistance in the wire.
Resistor is the name given to a component with pre determined resistance value. Resistance is a characteristic of many electrical appliances called load. Every circuit has certain resistance value
The resistance value of circuit wiring should be minimal to reduce electrical power loss. Some Energy source such as battery has internal resistance and should minimize. You can measure resistance in a circuit with Ohm meter. Unit of resistance is Ohm.

Voltage

In all electric circuits, electrical voltage is the pressure pushing current to flow in an electric circuit. Unit of electrical voltage is V. You can measure voltage in a circuit by voltmeter. A multimeter has different ranges to measure current, resistance and voltage. That is a multimeter, has Ammeter; Ohmmeter, and Voltmeter. Some versatile meter has more values to measure.

Electric Circuits Law

Ohm’s Law

The voltage across a conducting material is directly proportional to the  current through the material, that is, v = Ri, where R (resistance) is the proportionality constant. That is to say, voltage drop or potential difference along a conducting path is directly proportional to the current flowing in the material. Meanwhile, current flowing is a dependent on the resistance of the material.From the slope, you see that when current increase, voltage increases, and when current decreases, voltage also decreases.
With constant voltage, increase resistance, will reduce current. Reduce resistance will increase current. Current (I) = Voltage (V)/Resistance (R). Learn more as we move on to electrical calculations.