5-MAG-9

• 6.17 describe the structure of a transformer, and understand that a transformer changes the size of an alternating voltage by having different numbers of turns on the input and output sides
• 6.18 explain the use of step-up and step-down transformers in the largescale generation and transmission of electrical energy
• 6.19 know and use the relationship between input (primary)and output(secondary) voltages and the turns ratio for a transformer:

<math>V_p/V_s=N_p/N_s</math>

• 6.20 know and use the relationship:

input power = output power

<math> V_p I_p = V_s I_s </math>

for 100% efficiency

Plenary

• transformers don't work with d.c., only with a.c.!
• for a 100% efficient transformer, Power supplied in Primary = Power in Secondary
• Vp x Ip = Vs x Is

Homework

• do the question sheet (Science Shared)

Additional Information

Resources Required

• transformer demos

Website References

• None

Notes

• None