Electrical Charges

• a defibrillator is a device that gives a high energy electric shock to the heart of someone who is in cardiac arrest
• defibrillation needs a large amount of current to restore a heartbeat that has already stopped
• electric current is defined as the rate at which charge flows through the surface of a conductor
• electric charge is carried by particles called electrons
• CONVENTIONAL CURRENT is from the positive terminal of the battery to the negative terminal (Positive to Negative)
• •ELECTRON FLOW

  is from the negative terminal of the battery to the positive terminal (Negative to Positive)
• Most electrical signals carried by current's travel at a speed of 108 m/s.
• DRIFT - means a slow movement towards something
• DRIFT VELOCITY - defined as the average velocity attained by charged particles in a material due to electric field.
• CURRENT DENSITY -amount of electric current traveling per unit cross-section area and expressed in Amperes per square meter
• the higher is the current, the higher will be the current density.
• the more charges that flows through the cross-section of the wire per unit time, the greater is the current
• DRIFT VELOCITY is directly proportional to both the electrical current and current density.
• CONDUCTORS - are materials that permit electrons to flow freely from particle to particle.
• WIRE - used to connect the components of an electric current
• •VOLUME CONTROL KNOB - variable resistor that controls the volume of the sound
• VARIABLE RESISTOR - made of a long wire looped around insulator used to regulate current. - widely used in the different gadgets.
• Resistor - is an electrical component that limits or regulates the flow of an electrical current
• FIXED RESISTOR - resistor which possess fixed resistance
• Variable Resistor - resistor which provide variable value of resistance
• Carbon Film Resistor - fixed resistor where the resistive material is composed of carbon clay, and the leads of the resistor is made up of tinned copper
• Metal Film Resistor - fixed resistor type which uses a metal oxide film and the resistance can be adjusted by cutting the helical grove in the film