ΜΕΤΑΣΧΗΜΑΤΙΣΤΕΣ

Multiple Choice

What does the term "ΜΕΤΑΣΧΗΜΑΤΙΣΤΕΣ" refer to in the context of the lesson?

• Transformers

• Transistors

• Converters

• Modulators

Multiple Select

What are the classifications of M/S based on their characteristics?

• Tri-phase

• Mono-phase

• Strength

• Type of cooling

Multiple Choice

The voltmeter is at 0 in this image. How would you manipulate the experiment to create electricity (measured in volts)?

• Flip the magnet around so the North pole is facing out
• Move the magnet back and forth
• Take the magnet out
• Add more coils around the paper cylinder

Multiple Choice

What is the relationship between the primary and secondary coils in a transformer as shown in the image?

• Voltage ratio

• Current ratio

• Turns ratio

• Power ratio

Multiple Choice

What is the relationship between the power, voltage, and current in the transformer as shown in the image?

• Power is directly proportional to voltage

• Power is inversely proportional to current

• Power is equal to voltage times current

• Power is independent of voltage and current

Multiple Choice

Which component of a transformer does not actually make contact with the electrical energy but plays a crucial role in its operation?

• Primary winding

• Secondary winding

• Magnetic core

• Cooling system

Multiple Choice

What is the principle by which transformers operate?

• Electromagnetic induction

• Thermal induction

• Piezoelectric effect

• Capacitive coupling

Multiple Choice

What is the formula for calculating the percentage of the nominal voltage in a series circuit?

• uk% = U1K / U1N * 100

• uk% = U1N / U1K * 100

• uk% = U1K + U1N * 100

• uk% = U1K - U1N * 100

Multiple Choice

What is the formula to calculate the potential voltage of a secondary circuit in a transformer?

• I2K = I2N * 100 / uk%

• I2K = I2N / uk%

• I2K = I2N + uk%

• I2K = I2N - uk%

Multiple Choice

What are the characteristics of high and low tension types in construction materials?

• High tension: many strands - small diameter

• Low tension: few strands - large diameter

• High tension: few strands - large diameter

• Low tension: many strands - small diameter

Multiple Choice

What is the function of the components labeled as 'tύλιγμα Χ.Τ.' and 'tύλιγμα Y.T.' in the diagram?

• To provide insulation

• To generate magnetic fields

• To support the structure

• To connect electrical circuits

Multiple Choice

What are the main components labeled in the diagram of the transformer?

• Thermometer

• Cooling fins

• High voltage connections

• Low voltage connections

Multiple Choice

What is the function of the two coils in each core of the transformer shown in the image?

• To increase voltage

• To decrease voltage

• To store energy

• To convert AC to DC

Multiple Choice

What is the purpose of the connections shown in the diagrams?

• To illustrate series connections

• To demonstrate parallel connections

• To show the operation of a transformer

• To explain the function of a switch

Multiple Choice

What is the difference between the connections of high voltage and low voltage transformers as shown in the diagrams?

• High voltage transformers have larger connections

• Low voltage transformers have larger connections

• Both have the same size connections

• High voltage transformers are used for residential purposes

Multiple Choice

What are the voltage levels indicated in the circuit diagrams for the two configurations shown?

• 220V, 24V, 12V

• 220V, 40V, 6V

• 24V, 12V, 40V

• 12V, 6V, 220V

Multiple Choice

What type of connection is represented in the diagram on the left side?

• Star Connection

• Delta Connection

• Parallel Connection

• Series Connection

Multiple Choice

What is the relationship between Uπ and Uφ in the context of the diagrams shown?

• Uπ = √3 · Uφ

• Uπ = Uφ

• Uπ = Uφ/√3

• Uπ = 3 · Uφ

Multiple Choice

What is the role of the neutral connection in the primary and secondary phases as shown in the diagram?

• To provide electrical connection

• To create magnetic fields

• To balance the phases

• To isolate the phases

Multiple Choice

What is the purpose of the diagram shown in the image?

• To illustrate a three-phase transformer connection

• To show the wiring of a single-phase transformer

• To explain the operation of a DC motor

• To demonstrate a circuit diagram for a battery

Multiple Choice

What is the formula for apparent power (VA) in the first column?

• P_s=U·I

• P_s=I·R

• P_s=U/R

• P_s=U+I

Multiple Choice

What is the practical power given by a transformer when fed with voltage U2 and current I2?

• P2 = U2 * I2 * sinφ2

• P2 = 1.73 * U2 * I2 * sinφ2

• P2 = U1 * I1 * sinφ1

• P2 = 1.73 * U1 * I1 * sinφ1

Multiple Choice

What is the relationship of transfer 1:1 in terms of the primary and secondary classes?

• The primary class is equal to the secondary class

• The primary class is greater than the secondary class

• The primary class is less than the secondary class

• There is no relationship between the classes

Multiple Choice

What is the relationship between the power of the transformer and the two windings in the circuit?

• Power is equal to the sum of the two windings

• Power is the difference between the two windings

• Power is independent of the windings

• Power is only determined by the primary winding

Multiple Choice

What is the relationship expressed in the equation shown in the image?

• W1/W2 = U1/U2 = I1/I2

• W1 + W2 = U1 + U2

• W1 - W2 = U1 - U2

• W1 * W2 = U1 * U2

Multiple Choice

What are the advantages of automation as listed in the image?

• Low cost, lighter weight

• Higher efficiency, better performance

• Greater flexibility, lower maintenance

• Increased complexity, higher cost

Multiple Choice

What is the effect of changing the voltage of the secondary circuit in the diagram?

• It increases the current

• It decreases the current

• It has no effect

• It changes the resistance

Multiple Choice

What is the formula for calculating apparent power (VA) in the first column?

• P_s=U·I

• P_s=1.73·U·I

• P_s=U/I

• P_s=U+I