What is a wirewound resistor?
A Wirewound resistor is a resistor made with a conductive wire of a high resistivity. This wire is made of a special alloy and it is wound on a support tube of refractory material such as ceramics, porcelain, etc.
What is Direct Current? – DC
Direct Current (DC), is the result of the flow of electrons (negative charge) in a conductor (most of the time, wires of copper) that goes only in one direction.
What is Electrical Resistivity?
Electrical resistivity [ρ] (rho) is a characteristic of materials and has ohm-meter unit. Resistivity indicates how much the material opposes the flow of electric current.
Capacitor and Direct Current
If a battery is connected to a capacitor, it will allows no direct current (DC) to flow through. If a not charged capacitor is connected across the terminals of a battery, a transient current flows as the capacitor plates charge up.
Capacitor and Direct Current. Current starts from its maximum value and decreases to 0 amps. This current is called “transient current”.
The Superposition Theorem
The Superposition theorem states that the effect of two or more voltage sources in a resistor is equal to the sum of the individual effects of each source taken separately, replacing all the remaining voltage sources with short circuits.
What is Electrical Resistance? Obtaining a material’s resistance
The electrical resistance is a measurement of the opposition that offers a material to the passage of electrons (the electric current). When a material, such as metals has many free electrons, it allows the easy flow of electrons and it is called conductor.
First Right Hand Rule
The First Right Hand Rule or (Magnetic Force induced on a Current-Carrying Wire) says that if a current-carrying wire is in the presence of a magnetic field, a force is exerted on the wire.
Capacitor Discharge Process.
In a series RC circuit, a capacitor does not immediately discharge after being disconnected from a power source of direct current. The capacitor voltage Vc decreases from the initial voltage on the capacitor to 0 volts in some amount of time.
DC Motor
A DC motor is composed of a stator and a rotor. In many small motors, the stator is composed of magnets. Larger motors have windings.
Static Electricity – What it is?
Static electricity is static, since it is a current that is going nowhere. Both, DC and AC current flow in some direction, but estatic electricity does not.
Internal resistance of a voltage source
Voltage sources, whether batteries, generators, etc., are not ideal (perfect). A real voltage source is composed of an ideal voltage source in series with a resistance called internal resistance.
Temperature effects on resistance. Resistance Variation with Temperature.
The value of the resistance of a material varies with temperature change. For this reason, the circuit or system containing these elements should work in controled environment