Md Nazmul Islam

🔥 What is an Electrical Fire? An electrical fire starts from damaged or overheated electrical components, wiring, or appliances. These fires spread quickly and can cause severe property damage and loss of life. ⚠️ Common Causes of Electrical Fires Damaged wiring – worn, frayed, or loose wires overheat. Malfunctioning appliances – faulty cords,...

A photodiode is a semiconductor device that converts light into an electrical current. It operates in reverse bias and generates current when exposed to light. Working Principle A photodiode is made of a P-N junction. In reverse bias, the depletion region is wide, and very little current flows in darkness. When light photons...

A Light Emitting Diode (LED) is a semiconductor device that emits light when current flows through it in the forward direction. Unlike ordinary diodes, LEDs convert electrical energy into visible light (or infrared, depending on material). Working Principle (Explained with the Images) An LED is made of p-type and n-type semiconductor...

A Zener diode is a special type of diode designed to allow current to flow not only in the forward direction (like a normal diode) but also in the reverse direction when the voltage reaches a specific value called the Zener breakdown voltage. Working Principle (GIF Reference) In the GIF, the...

Definition: A PN junction diode works in two modes depending on how the external voltage is applied: Forward Bias: Current flows easily. Reverse Bias: Current is almost blocked. Forward Bias (GIF Reference): In the GIF: The P-side (pink) is connected to the positive terminal of the battery, and the N-side (blue) is connected to the...

Definition: A PN junction diode is formed when a p-type semiconductor (rich in holes) is joined with an n-type semiconductor (rich in electrons). The junction between them allows current to flow in only one direction — making it the simplest and most widely used semiconductor device. Explanation with GIF: The left side...

Intrinsic Semiconductor Definition: An intrinsic semiconductor is a pure form of semiconductor material (like silicon or germanium) with no impurities. Its electrical conductivity comes only from the breaking of covalent bonds due to heat, which generates equal numbers of free electrons and holes. Explanation with GIF: In the image, you see atoms arranged...

Electrical plans, wiring diagrams, and installation layouts all rely on standardized symbols. Consistency ensures that electricians, inspectors, and contractors all “speak the same language.” Standardized symbols reduce miscommunication, improve safety, and speed up installations. Key Points for Electricians Standardization is essential: Symbols must be clear, readable, and consistent. Safety & efficiency: Prevents mistakes, avoids...

Light fixture symbols help differentiate between types of lighting. Ceiling lights, for example, are often drawn as circles representing the light fixture itself. Solid lines extending from the circle show the direction of light or the fixture's coverage area. Meanwhile, wall lights are typically drawn as a half-circle or a...

Generic Switch Symbol It is the symbol of a generic switch in open condition. Closed switch It is a generic symbol for closed switch. a closed switch means the circuit is complete & current can flow through it. Thermal Magnetic Switch It is the symbol of thermal magnetic switch. it incorporates both electromagnetic  and...

Location Symbols for Installations Machine, general symbol* function etcLoad, general symbol* detailsMotor starter, general symbol* Indicates type etc.Socket-outlet, general symbol Twin Socket-outlet, general symbolSwitched socket-outlet Twin Switched socket-outletSwitch, general symbol2 way switch, single poleIntermediate switchPull switch, single-polePush buttonClock, general symbolBell (Audible)Buzzer (Audible)Siren (Audible)HornTelephone handset, general symbol Popular Symbols Making and breaking current SwitchSwitch- fuseFuse-switch Isolating Isolator (Disconnector),...

Electrical symbols are universal representations used in diagrams and schematics to show electrical components and connections clearly. Power Supply Schematic Symbols SchematicSymbolSymbol IdentificationDescription of SymbolSingle CellA single DC battery cell of 0.5VDC Battery SupplyA collection of single cells forming a DC battery supplyDC Voltage SourceA constant DC voltage supply of a...