The main components of a transformer are two coils (windings) that are electrica

Question

The main components of a transformer are two coils (windings) that are electrically insulated from each other. One coil, called the primary coil, is connected to a voltage source; the other, the secondary coil, delivers the power. The key factor is the number of turns in each coil.

If the number of turns in the primary coil is N1 and that in the secondary coil is N2, then we can write

V2V1=N2N1.

Note that if N2>N1, then V2>V1. In this case we have a step-up transformer. Conversely, if N2<N1, then V2<V1, and we are dealing with a step-downtransformer. Without energy losses, the power in the primary and secondary coils is the same:

V1I1=V2I2.

Explanation / Answer

part A:

with DC voltage, there is no alternating current ==> there is no alternating flux linkage that can induce voltage.
hence secondary voltage will be 0.

part B:
as we know ratio of voltage=ratio of turns

500/25=200/N2
N2=10

part C:
as we know ratio of currents=1/ratio of turns

500/25=1/(200/N2)

500/25=N2/200

N2=4000

part D:

as we know ratio of currents=1/ratio of turns

2.5/I2=1/(400/80)

2.5/I2=1/5

I2=2.5*5=12.5 A

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.