Electromagnetic Induction and Voltage Transformation

Question 1

is an object which is capable of producing magnetic field and attracting
unlike poles a n d repelling like poles.

Answer 1

magnet

Question 2

• It is the region in the neighborhood of a magnet, electric current, or changing electric field, in which magnetic forces are observable.

Answer 2

Magnetic field

Question 3

Electrical power available to a hospital or clinic provides up to about ___

Answer 3

480 V

Question 4

Much lower than the _____ needed for x-ray production.

Answer 4

20,000 to 150,000 V

Question 5

_____ are principal components of x-ray generators

Answer 5

Transformers

Question 6

They convert low voltage into high voltage

Answer 6

Transformers

Question 7

Transformers convert low voltage into high voltage through a process called

Answer 7

ELECTROMAGNETIC INDUCTION

Question 8

have two poles ,a northpole and a south pole.

Answer 8

Magnets

Question 9

The ____ is represented by field lines that start at a magnet’s north pole and end at the south pole.

Answer 9

magnetic field

Question 10

A magnet attracts some metals, mainly iron. This property of magnets to attract
metals is called _____.

Answer 10

magnetism

Question 11

The earliest magnets were described 2000 years ago as naturally occurring black stones that attracted iron.

Answer 11

Lodestones

Question 12

These “leading stones,” or lodestones, then known as _____ in the Greek language.

Answer 12

Magnesia

Question 13

• Small magnet created by the electron spin.

Answer 13

MAGNETIC DIPOLE

Question 14

• Accumulation of many dipoles.

Answer 14

MAGNETIC DOMAIN

Question 15

▪ Materials that are unaffected when brought into a magnetic field.
▪ Substances that are non-magnetic. (e.g., wood, water, some plastics)

Answer 15

DIAMAGNETIC

Question 16

▪ Materials that are between the classification of diamagnetic and
ferromagnetic.
▪ Slightly attracted to a magnet and loosely influenced by an external magnetic field.

Answer 16

PARAMAGNETIC

Question 17

▪ Strong attracted by a magnet and are magnetized easily.
▪ E.g., aluminum, nickel and cobalt (most useful magnets produced by ferromagnetic material)

Answer 17

FERROMAGNETIC

Question 18

Three principle types of magnets:

Answer 18

NATURAL MAGNETS
PERMANENT MAGNETS
ELECTROMAGNETS

Question 19

are available in many sizes and shapes but principally as bar or horseshoe-shaped magnets, usually made of iron.

Answer 19

permanent magnets

Question 20

are typically produced by aligning their domains in the field of an electromagnet.

Answer 20

Permanent magnets

Question 21

• consist of wire wrapped around an iron core.

Answer 21

Electromagnets

Question 22

is an effect that occurs with changing magnetic fields and alternating (AC) electrical current.

Answer 22

Electromagnetic induction

Question 23

A transformer with a turns ratio greater than 1 is a

Answer 23

Step-up transformer

Question 24

When the turns ratio is less than 1, the transformer is a

Answer 24

step-down transformer.

Question 25

The _______ is a square doughnut of magnetic material

Answer 25

closed core transformer

Question 26

• The ____ is not a single piece but rather is a built-up slab of laminated layers of iron.

Answer 26

closed-core transformer

Question 27

• An _____ consists of an iron core with only one winding of wire.

Answer 27

autotransformer

Question 28

An ______ is generally smaller, and because the primary and the secondary sides are connected to the same wire, its use is generally restricted to cases in which only a small step up or step down in voltage is required.

Answer 28

autotransformer

Question 29

• A ______ traps even more of the magnetic field of the primary winding and is thus a more efficient transformer than closed-core transformer.

Answer 29

shell-type transformer

Question 30

This type is more efficient than the closed-core transformer.

Answer 30

Shell-type

Question 31

Most currently used transformers are

Answer 31

shell type

Question 32

This type of transformer is used in modern x-ray equipment.

Answer 32

Shell type