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WorksheetsSA3 - Electrical Transformer
Total questions: 20
Worksheet time: 20mins
The transformer is a device used to .......... the value of a voltage.
steady
resist
change
anchor
If a transformer reduces voltage, it is called a....................... transformer.
step left
step right
step up
step down
A laminated transformer core reduces the amount of energy that is wasted in the form of........
solidifying
flux
heat
Why transformers work with A.C. current but not D.C.
A.C current produces changing magnetic field.
D.C current produces changing magnetic field.
D.C current is weak
A.C current is powerful
Which of the following does not change in a transformer?
Voltage
Current
Power
Frequency
This picture is an example of a ________________.
Motor
Generator
Step-up transformer
Step-down transformer
Ratio of voltages is equal to ratio of _______________________.
number of iron sheets in core
number of coil
number of turns in coil
number of electromagnetic
Transformer works on which of the following principle
Lenz’s Law
Ampere's Law
Faraday's Law of Electromagenetic Induction
Fleming's Law
What is the material used for construction of transformer core?
Aluminium
Copper
Iron
Wood
The winding of wire around a core which is connected to a source of alternating current (AC) energy is called the ....... coil.
primary
secondary
tertiary
If a transformer increases voltage, it is called a ......... transformer.
step right
step left
step up
step down
If a transformer reduces voltage, it is called a....................... transformer.
step left
step right
step up
step down
Can transformer works in DC circuit?
Yes
No
Why does transformer cannot be operated under DC condition?
DC current has less harmonics and frequency independent
No current can be transmitted
No changing flux, no induced voltage in the secondary
Mutual inductance is
interactions of one coils magnetic field on other coil as it induces a voltage in the adjacent coil
Interactions of one coils magnetic field on other coil as it induces a current in the adjacent coil.
Interactions of one coils magnetic field on other coil as it induces electrical energy in the adjacent coil
Induced voltage in primary and secondary winding depends on the following except for
Resistor, R
number of turns, N
magnetic flux
Frequency
Why does transformer core is laminated ?
Reduce the effect of eddy current
Minimize losses
Heat dissipation
To make it lighter and portable
Electrical symbol of a TRANSFORMER
The main use of current transformer AKA CT's is...
As measurement transformer
As Current controller
As Voltage regulator
In order for electromagnetic induction to occur, there must be relative............between a magnetic field and a conductor.
race
Motion
field
voltage
