Transformer Maintenance and Functions Quiz
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Questions and Answers

What is the primary function of an oil conservator in a transformer?

  • To maintain a constant oil level and manage oil expansion. (correct)
  • To detect gas leaks within the transformer.
  • To cool the transformer through air circulation.
  • To prevent mechanical damage during transportation.
  • Which device is crucial for preventing excessive internal pressure in a transformer tank?

  • Pressure relief valves. (correct)
  • Oil filler fittings.
  • Cooling tubes.
  • Gaskets and seals.
  • What is the initial step in calculating cooling tubes for a transformer?

  • Determine heat load. (correct)
  • Select cooling method.
  • Check for adequate cooling.
  • Calculate required cooling capacity.
  • Which of the following is NOT a feature typically found on a transformer tank?

    <p>Calculate oil viscosity.</p> Signup and view all the answers

    What is the significance of painting and coating a transformer tank?

    <p>To protect against corrosion and environmental exposure.</p> Signup and view all the answers

    What is the primary function of the primary winding in a transformer?

    <p>To receive electrical power from the source</p> Signup and view all the answers

    What distinguishes three-phase transformer windings from single-phase transformer windings?

    <p>They have three primary and three secondary windings</p> Signup and view all the answers

    How does the number of turns in the secondary winding affect a transformer?

    <p>It influences the voltage transformation ratio</p> Signup and view all the answers

    What is a unique feature of an auto-transformer compared to traditional transformers?

    <p>It has only one winding serving both roles</p> Signup and view all the answers

    Which type of winding arrangement is known for better insulation and a compact design?

    <p>Concentric Winding</p> Signup and view all the answers

    What is the main characteristic of high-voltage (HV) windings in transformers?

    <p>They usually have fewer turns than low-voltage windings</p> Signup and view all the answers

    Which material provides higher conductivity for transformer windings but may be more expensive?

    <p>Copper</p> Signup and view all the answers

    What is the purpose of sandwich winding in a transformer?

    <p>To reduce leakage inductance</p> Signup and view all the answers

    What shape do the windings take in a Delta connection?

    <p>Triangular</p> Signup and view all the answers

    Which factor is essential for determining the turns ratio in a transformer?

    <p>Desired output voltage</p> Signup and view all the answers

    What is the primary purpose of the no-load current in a transformer?

    <p>To establish the magnetic field</p> Signup and view all the answers

    What is the relationship between the magnetizing reactance (Xm) and the no-load current (I no-load)?

    <p>Xm equals V divided by I no-load</p> Signup and view all the answers

    What type of core is typically used in transformer design for better magnetic coupling?

    <p>Laminated iron core</p> Signup and view all the answers

    Which of the following is NOT a primary consideration when designing a transformer?

    <p>Color of the wires</p> Signup and view all the answers

    What is a key characteristic of the primary winding in a transformer?

    <p>It connects directly to the power source</p> Signup and view all the answers

    What happens when the secondary winding of a transformer is open-circuited?

    <p>Magnetizing current flows in the primary winding</p> Signup and view all the answers

    Which of the following factors influences the choice of core material in transformer design?

    <p>Magnetic properties and losses</p> Signup and view all the answers

    What do core losses in a transformer primarily consist of?

    <p>Hysteresis and eddy current losses</p> Signup and view all the answers

    What does the turns ratio in a transformer represent?

    <p>The ratio of primary winding turns to secondary winding turns</p> Signup and view all the answers

    How are the primary and secondary winding currents related?

    <p>I1 is inversely proportional to I2</p> Signup and view all the answers

    What is leakage flux in transformers?

    <p>Flux that completes its path through air instead of the core</p> Signup and view all the answers

    What is the effect of resistance and leakage reactance in a transformer?

    <p>They cause voltage drop in each winding.</p> Signup and view all the answers

    The frequency of the AC supply affects which component of the transformer?

    <p>Induced emf in the windings</p> Signup and view all the answers

    What occurs to the voltage transformation ratio when N2 is greater than N1?

    <p>The transformer is a step-up transformer.</p> Signup and view all the answers

    What type of forces primarily act within a transformer?

    <p>Electromagnetic forces</p> Signup and view all the answers

    What does the RMS value of induced emf in the primary winding depend on?

    <p>Maximum flux and frequency of the AC supply</p> Signup and view all the answers

    In a practical transformer, what happens to the self-induced emf due to leakage flux?

    <p>It reduces energy transmission.</p> Signup and view all the answers

    What is the average induced emf per turn in terms of frequency and flux?

    <p>4.44f Fm</p> Signup and view all the answers

    What causes mechanical stresses within a transformer during a short circuit?

    <p>High electromagnetic forces</p> Signup and view all the answers

    What is the primary function of transformer oil in oil-immersed cooling?

    <p>To act as both an insulator and a coolant</p> Signup and view all the answers

    Which cooling method uses forced air to improve heat exchange in transformers?

    <p>Oil Forced Air (OFA) Cooling</p> Signup and view all the answers

    What component is typically included within a transformer tank for safety monitoring?

    <p>Buchholz Relay</p> Signup and view all the answers

    What design consideration helps ensure the structural integrity of a transformer tank?

    <p>Adding reinforcements to stress areas</p> Signup and view all the answers

    What happens when the magnetic core of a transformer saturates?

    <p>It causes nonlinear behavior and increased forces.</p> Signup and view all the answers

    Which of these methods involves cooling transformers using water?

    <p>Oil Forced Water (OFW) Cooling</p> Signup and view all the answers

    What does the thermal cycling of a transformer typically result in?

    <p>Mechanical stresses due to expansion and contraction</p> Signup and view all the answers

    In which cooling method does natural convection play a key role?

    <p>Oil Natural Air Forced (ONAF) Cooling</p> Signup and view all the answers

    What type of construction method is commonly used for transformer tanks?

    <p>Welding or riveting</p> Signup and view all the answers

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