11 C Section Review

Question 1

Describe the basic construction of a transformer. What transfers electrical energy between the two coils?

Answer 1

AC input, AC output, insulated wires wrapped on opposites sides of a ferromagnetic core frame. Alternating current.

Question 2

In which coil of a transformer does the current determine the strength of the magnetic field in
the core?

Answer 2

The input coil.

Question 3

List at least four everyday applications of electromagnets.

Answer 3

Electric doorbell, buzzer, particles accelerators, and sorting metals.

Question 4

T or F: The strength of the magnetic field created by an electromagnet depends on the type of material in the core, the number of wraps of wire, and the amount of current in the wire.

Answer 4

True

Question 5

On September 22, 2006, twenty-three people died and ten were injured when an experimental maglev train in Germany moving at 133 km/h collided with a repair car accidentally left in the guideway. How should a Christian respond to such tragedies?

Answer 5

That the people are in the hands of The Lord and they will be okay with The Lord.

Question 6

An electrical substation for your neighborhood includes a transformer that supplies your street. Its input coil has 2450 wraps and its output coil has 490 wraps. If the input voltage is 115 kV, what is the voltage of the electrical supply to your street?

Answer 6

23 kV

vOut/vIn = nOut/nIn

vOut/115kV = 490/2450
vOut = (115k * 490)/2450
vOut = 23 kV