Question

A friend from abroad presents you a coffee maker when she visited you. Unfortunately, it was designed to operate at 110 V line to obtain 960 W power that it needs.

1. Which type of transformer you use to operate the coffee maker at 220 V?

2. Assuming the transformer you use as ideal, calculate the primary and secondary currents.

3. What is the resistance of the coffee maker?

Answer 1

1. Step down transformer.

2. Since the transformer is ideal

V_pI_p = V_s I_s = 960 W, V_p = 220 v, V_s = 110 v
V_pI_p =960

I_s = \(\frac{960}{110}\)= 8.72 A

3. R =  \(\frac{V^2}{P}=\frac{110^2}{960}\) = 12.60Ω