Download Transformers Practice #1

Transformers Practice #1
The generator at a nuclear power plant outputs
20.0 kV at 50.0 A into the primary coil of the
generating transformer. The primary coil has 8
loops and the secondary coil has 96 loops.
a. What type of transformer is this?
b. What is the power produced by the generator?
c. What is the voltage of the secondary coil?
d. What is the current of the secondary coil?
Transformers Practice #2
Some transmission lines carry electricity at 138
kV and 7.25 A. There are transformers to convert
the electricity before it reaches residential power
lines. The primary coil has 238 loops. The
secondary coil voltage is 4.06 kV.
a. What type of transformer is this?
b. How many loops are in the secondary coil?
c. What is the current of the secondary coil?
d. What is the power of the secondary coil?
Transformers Practice #3
There are step down transformers at every
power line before the line goes into a house.
The loop ratio is 108 and the secondary coil
voltage is 120 V. The power output of the
secondary coil is 9.59 kW.
a. What is the primary coil voltage?
b. What is the primary coil current?
c. What is the power output of the primary coil?
d. What is the secondary coil current?
Transformers Practice #4
Your laptop adaptor has an input voltage and
current of 120 V and 1.50 A. The primary coil
has 42 loops and the output voltage to the
laptop is 20.0 V.
a. What type of transformer is this?
b. How many loops are on the secondary coil?
c. What is the output current?
Transformers Answers
1.a) Step Up
1.b) 1.00 MW
1.c) 240 kV
1.d) 4.17 A
2.a) Step Down
2.b) 34 Loops
2.c) 246 A
2.d) 1.00 MW
3.a) 13.0 kV
3.b) .738 A
3.c) 9.59 kW
3.d) 79.9 A
4.a) Step Down
4.b) 7 Loops
4.c) 9.00 A