Register
Question 1
If you want to replace a defective capacitor but the replacements you find do not have enough capacitance, you can increase their capacitance by:
Correct Answer:
connecting two or more capacitors in parallel
Explanation:
Capacitances add when you connect capacitors in parallel, so the total capacitance becomes the sum of the individual values. This lets you compensate for not having a single capacitor with enough capacitance by combining several capacitors to reach or exceed the required value, while still across the same supply voltage. If you connected them in series, the effective capacitance would actually decrease, which would not help here. The other ideas about increasing voltage or modifying current don’t change the capacitance at all. So parallel connections are the practical way to raise the total capacitance.
Question 2
The boiling point of refrigerant is the same as which temperature?
Correct Answer:
Condensing temperature
Explanation:
At the heart of this is the idea of saturation temperature: for a given pressure, liquid and vapor are in equilibrium at a single temperature. That temperature is what you call the boiling point when the liquid is boiling, and the condensing temperature when the vapor is condensing. In a refrigeration cycle, the evaporator pressure sets the boiling (evaporation) temperature, while the condenser pressure sets the condensing temperature. Since both are the same saturation temperature on the pressure–temperature curve for the refrigerant, the boiling point is the same as the condensing temperature.
Question 3
In the relationship between horsepower and watts, which option is correct?
Correct Answer:
746 watts
Explanation:
Power is the rate of doing work, and horsepower is a traditional unit used for engines, while watts are the SI unit. The mechanical definition ties horsepower to a precise rate of work: 1 horsepower equals 550 foot-pounds of work every second. When you convert that to watts, you get about 745.7 watts, which is commonly rounded to 746 watts. So the correct choice reflects this standard conversion: 1 hp ≈ 746 W. The other numbers don’t match the conversion (1,000 W is about 1.34 hp, and the others are around 4 hp), so they’re not the right equivalent.
Question 4
The external equalizer line used with a thermostatic expansion valve is to compensate for which phenomenon?
Correct Answer:
Refrigerant friction through the evaporator
Explanation:
The external equalizer line is used to account for pressure losses inside the evaporator caused by refrigerant flowing through it. As the refrigerant moves along the evaporator coils, friction creates a pressure drop from the inlet to the outlet. If the valve sensed pressure upstream, it would meter refrigerant based on a higher pressure than actually present at the evaporator outlet, leading to improper flow and unstable superheat. By delivering the evaporator outlet pressure through the external equalizer, the TXV responds to the true evaporating pressure where the refrigerant exits the coil, allowing it to meter more accurately and maintain the desired superheat.
Question 5
A refrigeration system has a hand-operated needle valve for the refrigerant expansion device. If refrigeration load and suction pressure remain constant, a decrease in condensing temperature will:
Correct Answer:
Result in reduced refrigerant flow unless the valve is opened
Explanation:
The key idea is how the expansion device gets its driving force. Flow through a hand-operated needle valve depends on the pressure difference between the high-pressure side (condenser) and the low-pressure side (evaporator), plus how open the valve is. If the condensing (high-side) temperature falls while the suction pressure stays the same, the high-side pressure drops. That reduces the pressure difference across the valve. With a fixed valve setting, this smaller driving force means less refrigerant can flow through the valve. Since the load and suction conditions aren’t changing, the system won’t automatically increase flow—you’d need to open the valve more to allow more refrigerant to pass. So, refrigerant flow will be reduced unless the valve is opened.
Question 1
Exam overview

About this Exam

The UA Service, Training, and Recognition (STAR) Certification is a premier credential for professionals in the HVACR and plumbing industries. Developed by the United Association (UA), this certification signifies a high level of expertise, dedication, and competence in servicing and installing complex piping and mechanical systems. It is designed for experienced journey-level workers who have completed their apprenticeship and are looking to validate their skills against a national standard of excellence. Earning the UA STAR demonstrates that you possess the advanced knowledge required for demanding, highly specialized work in the field

More details

Additional Information

What the Course Entails and Exam Details

The UA STAR exam covers a comprehensive array of technical topics critical for advanced mechanical system service and installation. While specific course structures may vary by training center, the certification curriculum generally focuses on these core domains:

Advanced Plumbing and Pipefitting Techniques: Master precision installation methods and repair strategies for commercial and industrial piping systems.

HVACR Systems Diagnosis and Repair: Gain deep expertise in diagnosing complex issues and servicing diverse heating, ventilation, air conditioning, and refrigeration systems.

Code Compliance: Ensure adherence to relevant national and local plumbing, mechanical, and fuel gas codes.

Safety Standards: Understand and apply rigorous OSHA regulations and industry-specific safety protocols.

Blueprint Reading and Plan Interpretation: Accurately interpret detailed architectural drawings and mechanical specifications.

Hydronics and Steam Systems: Learn specialized installation and maintenance procedures for fluid-based heating and cooling systems.

 

 

 What to Expect in the Final Exam

The UA STAR certification exam is a rigorous assessment designed to challenge your knowledge and practical problem-solving abilities. It typically involves a standardized written component.

The exam consists primarily of multiple-choice questions, requiring you to select the best answer from several options.

Achieving a passing score is a requirement, demonstrating that you have met the high standard of proficiency set by the UA. The exact passing score threshold is communicated to you during your registration process and is subject to standardized assessment methods.

Expect the exam to be timed, which ensures efficient completion and reflects real-world decision-making urgency in the trade. Details on the time limit are typically provided during your exam registration or briefing.

Strict rules apply, and cheating or sharing exam content is prohibited, with severe consequences including disqualification.

 

 

 How to Study and Exam Centers

Effectively preparing for the UA STAR exam requires a dedicated study strategy combining theoretical review and practical experience.

Review Core Curriculum Materials: Thoroughly study the UA STAR-related textbooks, training manuals, and resources provided during your training or designated by your local UA program.

Utilize UA STAR Practice Exams: Taking practice tests is highly encouraged to identify knowledge gaps, familiarize yourself with the question format, and practice time management under simulated exam conditions.

Attend specialized training workshops: Your local UA training center may offer refresher courses or focused workshops specifically targeting key exam topics.

Focus on Weak Areas: Spend extra time reviewing subjects you find challenging, consulting with experienced mentors or instructors when necessary.

Regarding exam locations, the UA STAR exam is typically administered at authorized training centers within the UA network. Your local UA union or joint apprenticeship and training committee (JATC) is your primary point of contact for information regarding available exam centers, registration procedures, and scheduled testing dates.

 

 

Job Opportunities from the Course

Earning the UA STAR certification significantly enhances your career prospects and opens doors to diverse high-skill job opportunities in the specialized piping and mechanical trades. Graduates of the program are well-prepared for roles such as:

  • Commercial Plumber: Install, repair, and maintain plumbing systems in commercial buildings.
  • Industrial Pipefitter: Assemble, install, and service piping systems for industrial facilities.
  • HVACR Technician (Advanced): Troubleshoot, repair, and service complex heating, air conditioning, and refrigeration systems in large-scale applications.
  • Service Technician Specialist: Provide specialized maintenance and repair services for critical piping and mechanical infrastructure.
  • Steamfitter/Piping Specialist: Install and maintain high-pressure piping and steam systems in varied settings.
  • Site Supervisor or Foreman: Lead and oversee teams of pipefitters, plumbers, and technicians on major construction projects.
  • Project Manager: Manage mechanical and piping projects from planning to execution and completion.

Instructor (UA Training): Train the next generation of apprentices in the trade

Quiz information

Frequently Asked Questions

The complete question count is available after full access is unlocked.
No fixed duration is currently configured for this quiz.
Question explanations are included where they are available in the quiz content, helping you review the reasoning after answering.
Yes. You can retake the practice test again as you continue studying during your available access period.
After your access is confirmed, you can continue into the complete practice exam from this quiz flow.
Unless explicitly stated otherwise, this page provides independent practice material for study and exam preparation and is not the official examination itself.
Keep studying

Related Questions

10-Hour Digital Training Course One Way Driving Ontario Practice Exam Prep Guide

0 min

200 Hour Yoga Teacher Training Practice Exam

0 min

360 Training Food Handlers Practice Exam

0 min

360 Training Food Manager Practice Exam

0 min

3F151 Food Service UREs Practice Exam

0 min

40-Hour RBT Training Practice Exam

0 min