Transformers

The function of a transformer is to ...

• raise and lower the apparent power levels

• transfer DC voltage from the primary winding to the secondary winding

• increase or decrease A.C voltage or A.C current levels

• transform mechanical energy into electrical energy

Tags

NGSS.HS-PS3-3

A step up transformer has its primary winding to secondary winding ratio

• Greater than 1

• Equal to 1

• Less than 1

• Unknown

Primary winding of a transformer is determined by ...

• which winding is nearer to the load

• which winding is connected to the source

• which winding has more turns

• which side has the highest voltage

Tags

NGSS.HS-PS3-5

Choose the correct statement:

• The ratio of the secondary voltage to the primary voltage is equal to the ratio of the primary turn to the secondary turn

• The ratio of the primary current to the secondary current is equal to the ratio of the primary voltage to the secondary voltage

• The ratio of the primary apparent power to the secondary apparent power is equal to the ration of the primary voltage to the secondary voltage

• The ratio of the secondary current to the primary current is equal to the ratio of the primary turn to the secondary turn

Assume primary has 240 turns and secondary has 60 turns. Primary is connected with 120V AC power supply. What is the voltage on the secondary?

• 30 V

• 0.333 V

• 2 V

• 120V

Ratio of voltages is equal to ratio of

• iron sheets in core
• coil
• number of turns in coil
• all of above

This picture is an example of a ___________

• Step- Up Transformer
• Step- Down Transformer
• Motor
• Generator

Tags

NGSS.HS-PS2-5

NGSS.HS-PS3-3

Laminated insulation are normally used in the transformer:

• To reduce the hysteresis effect

• To increase the hysteresis effect

• To reduce the effect of eddy current

• To increase the effect of eddy current

If the primary power of an ideal transformer having a 2:1 voltage ratio is 100 W, the secondary power is:

• 200 W

• 75 W

• 50 W

• 100 W

Tags

NGSS.HS-PS3-2

NGSS.HS-PS3-3

A transformer does not change the following:

• Frequency

• Voltage

• Current

• None of these