Md Nazmul Islam

This diagram shows the basic electrical wiring for controlling a fan and bulb using separate switches. It’s a simple and essential household circuit that helps you understand how power flows through switches to operate electrical loads safely. Key Components: Fuse: Provides circuit protection from overloads or short circuits. Switches: Control the fan...

This image shows the most commonly used electrical holders and pliers that every electrician should know. Holders are used to safely connect light bulbs, while pliers are essential for gripping, cutting, and shaping wires during installation and repair. Types of Electrical Holders: Burfi Holder: Used for wall or ceiling mounting. Angle Holder:...

This diagram shows how to wire a single room with an inverter backup system. The setup ensures that essential appliances like a fan and bulb continue working during power outages. The MCB provides circuit protection, while the inverter automatically switches to battery power when the main supply fails. The wiring...

🌟 Star Connection vs 🔺 Delta Connection Star Connection (Y): Each phase winding is connected to a common neutral point. Phase voltage = Line voltage ÷ √3. Used for starting motors with reduced voltage and current. Suitable for long-distance transmission due to lower current. Delta Connection (Δ): Windings are connected end-to-end forming a closed loop. Phase voltage...

Grounding and Bonding: How Are They Different? Grounding and bonding are often confused, but they’re not the same. Both work together to keep electrical systems safe. Grounding → Connecting an electrical system to the earth, using a grounding electrode. This stabilizes voltage and helps clear faults. Bonding → Connecting metal parts (that...

Working at heights on electricity network poles and structures involves serious risks such as falls and electrical hazards. Proper training, equipment, and safe practices are essential to protect workers and comply with MBIE best practice guidelines (NZ). 🔺 Hazards of Working at Heights Falls from poles, towers, or scaffolds Electrical contact with...

🔥 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...