Page 173 - Physics Form 5 KSSM_Neat

Figure 4.32 shows the structure of a simple transformer and CHAPTER 4
Figure 4.33 shows the flow map for the working principle of a Brain-Teaser
simple transformer. Why does the transformer not work
with a direct current power supply? Electromagnetism

Laminated soft iron core
A.C. power
supply Info
KEMENTERIAN PENDIDIKAN MALAYSIA
Leakage of Step-down transformer:
V
P magnetic flux N , N ➪ V , V P
P
S
S
Step-up transformer:
Primary coil
Numbers of turns, N N . N ➪ V . V
P
P
S
S
P V
S Output
Magnetic field lines
terminals SCAN ME
SCAN ME
Secondary coil Video on the
Numbers of turns, N
S working principle
of a transformer
Figure 4.32 Structure of a simple transformer
http://bit.ly/32BBjR1
Primary circuit
A.C. power supply The alternating current
produces an produces a magnetic field
alternating current that changes in magnitude
in the primary coil. and direction.
The magnetic flux from the
primary coil is linked to the
Secondary circuit secondary coil through the
soft iron core.
The changing magnetic field induces V N
an alternating voltage across the V s = N s
secondary coil. p p

Figure 4.33 Working principle of a simple transformer
Ideal Transformer
Figure 4.34 shows an electrical I I
equipment connected to P S
the output terminals of a
transformer. The transformer
Power
receives input power from the supply Input power Output power Electrical
equipment
power supply and supplies the V V
output power to the electrical P S
equipment. Therefore, electrical Primary circuit Secondary circuit
energy is transferred from
the primary circuit to the Figure 4.34 Electrical equipment connected to the output terminals
secondary circuit.

LS 4.3.1 4.3.2 163