The operational amplifier is a widely used component in analogue electronic circuits. Besides, it is quite cheap chip and can be found almost everywhere. We design around it circuits like controllers, active filters, oscillators and many others analogue circuits. Any student in electronic field must be familiar with this chip; this will be with many scientific returns to him. The most familiar op-amp which is being in use for already decades is the uA741. This book is based on lecturing theory and giving example classes for more than a decade. Hundreds of books deal with the theory of electronic circuits in a professional and educational manner. The aim of manuscript is not to be part of this valuable collection of these books but just a tool to guide and accompany the students to solve and understand op-amps problems in a pedagogical and easy manner. This manuscript tends to give the student the ability to analyse a circuit and from the additional information, calculate the required values and answer all type of questions regarding the circuit under study.