This document entails comprehensive information about AC and DC power and motors and generators, including definitions, diagrams and additional information to ensure a thorough understanding of the concepts. All of the information needed to calculate the answers to the difficult questions in examin...
ALTERNATING CURRENT
Voltage vs Time & Current vs Time
Reducing the emf of a current
Advantages of Alternating Current
IMPORTANT CONCEPTS DC MOTORS, AC GENERATORS
& DC GENERATORS
Table comparing Energy conversion, Type of Current
used/produced, Structure, Function & Rules/Laws
applied and uses
Exam Guidelines
ALTERNATING CURRENT
AC generators produce an alternating current due to the fact that the current induced in the
coil/wires inside the generator is continuously changing direction and size. This change is best
illustrated in the Current vs time graph below:
Current vs Time Sine Graph
, 2
The peaks in the current (both positive & negative) correspond to where the coil is moving at
90° to the magnetic field.
When the coil is moving parallel to the magnetic field the current is ZERO.
The Voltage vs Time Graph (also a Sine Graph)
South Africa’s electricity supply ranges between 220 V and 240 V (these values are not the
maximum values of the voltage produced, but are statistical averages of the voltage
supplied).
This statistical average is described as the Root Mean Square or rms value.
The Vrms (root mean square voltage) is smaller than the maximum voltage by a factor of
and has the following equation:
Vrms =
Graphical representation follows below:
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller fatimakarjieker. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $4.81. You're not tied to anything after your purchase.
