What is Flip Flop:

A bistable multivibrator. A circuit which has two output states and is switched from one to the other by means of an external signal (trigger).

How to Design Heat sink for IGBT?

Any fined aluminum extrusion with a flat smooth surface can be used then your IGBT is mounted on it with a layer of silicon grease in-between, but remember the mounting surface is also your collector, if your heat sink is going to touch other metal parts it is beter to electrically insulate the IGBT with a silicon insulator strip and insulating sleeves for the mounting screws, then the heat sink can be mounted on a box that is fitted with a cooling fan with the fins inside the box, else it can be mounted open with the fins in a vertical position for natural airflow over the fins

Lenz's Law

Fleming Right Hand Rule:

Fleming Right Hand Rule:
As per Faraday’s law of electromagnetic induction, whenever a conductor moves inside a magnetic field, there will be an induced current in it. If this conductor is forcefully moved inside the magnetic field, there will be a relation between the direction of applied force, magnetic field and the electric current. This relation among these three directions, is determined by by Fleming Right Hand Rule

Operational Amplifier

An operational amplifier (op-amp) is a DC-coupled high-gain electronic voltage amplifier with a differential input and, usually, a single-ended output. In this configuration, an op-amp produces an output potential (relative to circuit ground) that is typically hundreds of thousands of times larger than the potential difference between its input terminals.

A proportional-integral-derivative controller (PID controller) is a generic control loop feedback mechanism (controller) widely used in industrial control systems. A PID controller calculates an "error" value as the difference between a measured process variable and a desired setpoint. The controller attempts to minimize the error by adjusting the process control inputs.

DC Motor

A DC motor is a mechanically commutated electric moto powered from direct current (DC). The stator is stationary in space by definition and therefore the current in the rotor is switched by the commutator to also be stationary in space. This is how the relative angle between the stator and rotor magnetic flux is maintained near 90 degrees, which generates the maximum torque.