Step-up transformer is an electric device that raises the voltage of the secondary side (winding) 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. As we …
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. …
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 …
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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. …
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 …
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 the dc series motors and universal motors. …
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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 …
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 …
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 perform two functions. It serves as …
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 …