Step-up Transformer

Step-up transformer

Step-up transformer is a transformer which raises the voltage of the secondary side (winding) of the transformer to the primary side (winding). A transformer is a static device that is used to step up voltage and step down the voltage. Power remains the same on the primary side and the secondary side of the transformer. … Read more

Electrical Power Generation MCQs

electrical power generation mcqs, hydro power is cheap source

Q # 01. Which one is the cheapest electrical power generation Source   A. Hydro Power Plant C. Diesel Power Plant B. Nuclear Power Plant D. Thermal Power Plant Correct Answer: Hydro Power Plant Q # 02. Coal Power plant also known as A. Charcoal Power Plant B. Steam Power Plant C. Thermal Power Plant D. … Read more

Synchronous Motor Working Principle and Construction

Synchronous Motor Working Principle and Construction

Synchronous motor construction is very similar to synchronous generator construction except that most motors are salient-pole machines. Principle and Operation of Synchronous Motor When an induction motor is connected to a three-phase supply, a rotating magnetic field is established; this induces currents in the rotor windings, thereby producing a torque. The rotor can never turn at … Read more

History, Discovery and Electricity Terminology

electricity invention

History and Discovery of Electricity Electricity is one of our most useful sources of energy today. It is hard to imagine how a modem industrial society could exist without electricity. But until the mid-1800s, no one knew much about electricity or how to use it. Until then, electricity was nothing more than a scientific curiosity. … Read more

DC Shunt & Series Motor on AC Power Supply

dc motor on ac supply

Operating a DC Shunt Motor on AC Power What will happen if you connect a dc motor to an ac source? When the ac source changes polarity, the current in the motor will reverse. But the reversal will occur in both the armature winding and the field winding. Therefore, the torque on the armature will … Read more

Universal Motor Characteristics, Speed Control and Life

universal motor parts

Universal Motors The universal motor is a special kind of ac series motor that performs almost as well as a dc motor. It delivers a high starting torque, its speed can be adjusted, it is small in size, and it is inexpensive. There are two main differences between dc series motors and universal motors. The … Read more

Transformer Cooling Methods and Systems

Transformer Cooling methods

Transformer Cooling Methods A transformer in operation develops heat as a result of the copper and core losses during operation. Heat is not produced rapidly in small transformers, but the rate is much higher in large transformers. The rate of heat production determines how high the operating temperature rises above the ambient temperature. There are many  … Read more

Autotransformer Application and Construction

autotransformer application

Autotransformer Introduction The prefix auto means self. An autotransformer is a self-induced transformer. It has the primary and secondary windings electrically connected. When the transformer is used as a step-down transformer, the entire winding serves as the primary winding. The section XY is common to both the primary and secondary windings. As with the two-winding … Read more

Instrument Transformers Applications & Types

Instrument Transformers Application

Instrument Transformers Current transformer and voltage transformer measuring instrument transformers are designed to operate at low current and low voltage. Safety is also a reason for not connecting test instruments to sources operating at high voltage. An instrument transformer reduces high voltages and currents to safe values. Instrument transformers performs two functions. It serves as … Read more

Transformer Construction and Types of Cores

Transformer Construction

Basic Transformer Construction A transformer consists of two coils mounted in fixed positions relative to each other. One coil is supplied by an alternating current. As the current alternates, the magnetic field it produces also alternates. This alternating field induces an alternating current in the second coil, which supplies a load. A simple transformer construction consists … Read more