141 S5 A

What is the primary function of step-up transformers used in national electrical transmission?

• A) To decrease voltage
• B) To transform electricity into mechanical energy
• C) To increase voltage
• D) To regulate current

What is the advantage of using auto-transformers?

• A) They are more efficient
• B) They have multiple windings
• C) They are smaller in size
• D) They are safer in case of a fault

What is the role of external radiators in large power transformers?

• A) To increase the oil temperature
• B) To reduce the oil circulation
• C) To improve cooling by natural convection
• D) To generate electricity

In what application are safety isolating transformers commonly used?

• A) Laboratory experiments
• B) Starting induction motors
• C) Bathroom shaver supply
• D) High-voltage transmission

Why are instrument transformers used in large power circuits?

• A) To increase energy efficiency
• B) To reduce electrical losses
• C) To measure current and voltage safely
• D) To regulate the frequency of electricity

What is the primary purpose of a centre-tapped safety transformer?

• A) To increase voltage
• B) To decrease voltage
• C) To provide a direct connection to earth
• D) To amplify electrical signals

What is the main advantage of using centre-tapped systems for portable power tools?

• A) Increased efficiency
• B) Greater power output
• C) Enhanced tool durability
• D) Reduced risk of electrical shock

What type of supply is provided by a safety isolating transformer in areas with an increased risk of electric shock?

• A) High voltage
• B) Low voltage
• C) Medium voltage
• D) Extra-low voltage

Why is it essential to verify the performance of Safety Critical Elements (SCEs)?

• A) To increase the cost of maintenance
• B) To meet manufacturer's guidelines
• C) To ensure safety in critical operations
• D) To reduce the need for inspections

What role does the oil play in power transformers besides cooling?

• A) Generating electricity
• B) Providing insulation
• C) Increasing voltage
• D) Regulating frequency