Focus Physics

The transformer

Core concepts and learning points for this section:

Syllabus Points

Core

  • 4.5.6.1 Describe the construction of a simple transformer with a soft-iron core, as used for voltage transformations
  • 4.5.6.2 Use the terms primary, secondary, step-up and step-down
  • 4.5.6.3 Recall and use the equation V N p p = V N s s where p and s refer to primary and secondary
  • 4.5.6.4 Describe the use of transformers in high- voltage transmission of electricity
  • 4.5.6.5 State the advantages of high-voltage transmission

Supplement

  • 4.5.6.6 Explain the principle of operation of a simple iron-cored transformer
  • 4.5.6.7 Recall and use the equation for 100% efficiency in a transformer I V = I V p p s s where p and s refer to primary and secondary
  • 4.5.6.8 Recall and use the equation 2 P = I R to explain why power losses in cables are smaller when the voltage is greater www.cambridgeinternational.org/igcse 33 Subject content