P

Positive ion

Atom that has lost one or more valence electrons.

Potential difference

Voltage difference between two points which causes current to flow in a closed circuit.

Peak

Maximum or highest amplitude level.

Phase

Angular relationship between two waves.

Photoconductive cell

Material whose resistance decreases and conductance increases on being exposed to light.

Photo detector

Component used to detect or sense light.

Photometer

Meter used to calculate light intensity.

Photon

A particle of light.

Photo resistor

Also known as a photoconductive cell or light dependent resistor. An electronic component whose resistance is inversely proportional to the intensity of incident light

Photovoltaic cell

Commonly called a solar cell used to convert light energy into electrical energy.

Piezoelectric effect

the direct conversion of electrical to mechanical energy or vice versa in some crystalline materials. Converts mechanical energy into electrical energy and electrical energy into mechanical energy.

Pnp transistor

A bipolar junction transistor with an n-type base and p-type emitter and collector.

Pole

In an active filter, a single RC circuit.

Polarity

Used to describe positive and negative charges.

Positive charge

having a higher electric potential

Potential energy

Energy that has potential to do work & has potential to be converted into other forms of energy, such as kinetic energy.

Potentiometer

A variable resistor with three terminals.

Power

The amount of work done per unit of time.Measured in units of watts. (joules/second).

Power amplifier

An amplifier designed to give maximum power output to a load.

Power dissipation

Amount of heat energy generated by a device in one second when current flows from it.

Power loss

Ratio of power absorbed to power delivered.

Power supply

Electrical equipment used to deliver either AC or DC voltage.

Primary

First winding of a transformer.

Printed circuit board -PCB

a thin plate on which chips and other electronic components are placed

Propagation

Movement of electromagnetic, electrical or sound waves through a medium.

Pulse

Rise and fall of some quantity for a period of time.

Pulse fall time

Time for a pulse to decrease from 90% of its peak value to 10% of its peak value.

Pulse rise time

Time required for a pulse to increase from 10% of its peak value to 90% of its peak value.

Pass band

The range of frequencies that will be allowed and amplified by a tuned amplifier.

Passive component

Component that does not amplify a signal.

Passive filter

A filter that contains only passive or non amplifying components