Electrical terminology

• Electricity : The flow of free electron in a close circuit called electricity

• Current: The flow of electron through a conductor in a close circuit is called current.

• Direct current: The current which does not change its direction and magnitude produced by dc generator.

• Alternating Current: The current which changes its direction and magnitude –produce by AC generator.

• Conventional current: The current flow negative to positive (USA.)

• Circuit : To provide one or more complete electrical path made by conductor.

• Cell: Combination of two electrodes surrounded by electrolyte for the purpose of producing voltage .

• Battery: Combination of two or more cell called battery

• Capacity : A battery or cell total available current

• Relay: An electric switch operated by an electromagnet, An electromagnet device having fixed core and a pivoting mechanical linkage.

• Switch : A device for operating and closing an electrical circuit- acts as controlling device.

• Circuit breaker: A device open the circuit automatically if when excessive current flow than predetermined value.

• Current Limiter: A device installed in a circuit to prevent current from increasing above a specific limit.

• Fuse: A metal strip melts when overheated by excess current.

• Generator: A machine which convert mechanical energy into electrical energy.

• Motor : A machine which convert electrical energy into mechanical energy.

• Armature : In a DC generator or motor the rotating part in an AC generator armature is mostly stationary part.

• Armature reaction: The interaction of armature with field of a Generator/the distortion of main field by armature called armature reaction.

• Brush : A device designed to provide an electric contact between a stationary conductor and rotating element.

• Magnet: A solid material that has the property of attracting substance containing iron.

• Magnetic field: A space where magnetic lines of force exist

• Magnetic lines of force: The magnetic field around a magnet represented by imaginary lines called magnetic lines of force.

• Properties of magnetic field lines : – They are like stretched bond which tend to be as

short as possible– They repel each other– They never cross each other.

• Commutator : A mechanical rotating switch which convert alternating voltage generated in the armature winding into direct voltage across the brushes, ie It is reversed the coil connection to the load.

• Slip rings: Conductive rings used with brushes for collecting AC voltage from armature to the load.

• Busbar: A power distribution point from where a number of circuit may be connected.

• Conductor : A materials through which an electric current can pass easily.

• Coil : One or more turns of conductor used in a circuit to produce inductance or electromagnetic field.

• Cycle: One complete set of positive and negative values of an alternating quantity is known as cycle.

• Time period: Time taken to complete one complete cycle of an alternating quantity

• RMS or effective value: Of an AC is equal to the direct current which result in the same expenditure of energy under the same condition.

• Capacitor: Two adjacent conductor separated by dielectric which store electricity.

• Capacitance: The property of capacitor is called capacitance • Capacitive reactance: The reaction or effect of capacitor in a

circuit is called capacitive reactance

• Cell: Combination of two electrodes surrounded by electrolyte for the purpose of producing voltage .

• Battery: Combination of two or more cell called battery

• Capacity : A battery or cell total available current

• Ground– an electrical connection to the earth.– Common connecting device of electrical circuit for zero

potential.• Bonding : The electric conductors by which

connecting together of metal structures to maintain uniform electric potential among all the parts.

• Cable: A group of insulated electric conductor usually covered with rubber or plastic.

• Wire : Without insulated electric conductor.