Energy Resources and Power

Question 1

What is the voltage ratio for a transformer?

Answer 1

p = primary

s = secondary

V_s/V_p = N_s/N_p

Question 2

What is the current ratio for a transformer?

Answer 2

I_s/I_p = N_p/N_s

Question 3

What are the two sources of loss of a transformer?

Answer 3

1. Iron Loss - due to eddy currents and hysteresis losses in the core. This source of loss is approximately constant with the load.
2. Copper loss - due to the I₂ R losses in the transformer windings. This source of loss, varies with the square of the current.

Question 4

Transformer Efficiency eq

Answer 4

Efficiency = Ouput Power / (Output Power +Losses) = (Input power - Losses)/ Input Power