Physics 7.3.5

Question 1

What is a ‘Transformer’?

Answer 1

A Transformer is an Electrical Device that can be Used to Increase or Decrease the Voltage / PD of an Alternating Current.

Question 2

A Transformer is an Electrical Device that can be Used to Increase or Decrease the ___ of an ___ ___. This is Achieved via Application of the…

Answer 2

Voltage / PD, Alternating Current. Generator Effect.

Question 3

A Basic Transformer Consists of: (3)

Answer 3

-Primary Coil.

-Secondary Coil.

-(Magnetic Field in the) Iron Core.

Question 4

Why is Iron the Metal Often Used as a Core in Electromagnets?

Answer 4

Because it is Easily Magnetised.

Question 5

Explain how a Transformer Works: (6)

Answer 5

-An Alternating Current is Supplied to the Primary Coil.

-The Current is Constantly Changing Direction. This Means that it will Produce a Changing Magnetic Field Around the Primary Coil.

-The Iron Core is Easily Magnetised, so the Changing Magnetic Field Passes Through it.

-As a Result, there is now a Changing Magnetic Field, Inside the Secondary Coil. This Changing Field Cuts Through the Secondary Coil, & Induces a Potential Difference.

-As the Magnetic Field is Constantly Changing (because it’s Caused by A.C.), the PD. Induced will be Alternating. The Alternating PD will have the Same Frequency as the Alternating Current that is being Supplied to the Primary Coil.

-If the Secondary Coil is Part of a Complete Circuit, it will Cause an Alternating Current to Flow.

-If the SC has Less Coils than the PC, then it is a Step-Down Transformer, & PD in the SC is Less than in the PC.

-If the SC has More Coils than the PC, then it is a Step-Up Transformer, & PD in the SC is More than in the PC.