Quick questions on Transformers and AC transmission: HSC Physics Module 6

4short Q&A pairs drawn directly from our worked dot-point answer. For full context and worked exam questions, read the parent dot-point page.

What is the four losses in a real transformer?

Show answer

Typical efficiencies: 95 percent for small transformers, above 99 percent for large grid transformers.

What is q1?

Show answer

Write the ideal-transformer voltage ratio and explain why transformers do not work on DC. [2 marks]

What is q2?

Show answer

A transformer steps

240 \text{ V}

down to

12 \text{ V}

with

400

primary turns. (a) Find the number of secondary turns. (b) If the secondary delivers

5.0 \text{ A}

to a load, find the primary current (ideal).

What is q3?

Show answer

33 \text{ kV}

rural feeder delivers

5.0 \text{ MW}

over a line of resistance

4.0 \Omega

(total return path). (a) Calculate the line current. (b) Calculate the

I^2 R

loss as a percentage of the transmitted power.

Have a question we have not covered?

This dot-point answer is short enough that we have not extracted many short questions yet. Read the full dot-point answer or ask Mo, our study assistant, in the chat for follow ups.

All PhysicsQ&A pages