Transformer Inefficiencies

• What are the sources of inefficiencies in a transformer?

  Core and wires
• Why do coils of wire in a transformer cause energy loss?

  They have resistance causing heat loss
• How does the size of the current affect heat energy loss in a transformer?

  Larger currents increase heat energy loss
• What causes inefficiencies in the core of a transformer?

  Induced eddy currents, magnetism reversal, poor insulation
• What are the ways to reduce energy loss in a transformer?

  • Use soft iron or iron alloys for the core
  • Laminate the core
  • Use thick wires, especially in secondary coils
  • Ensure core links all flux from primary to secondary coil
• Why are energy losses significant in transmission lines?

  Electrical energy is transmitted over long distances
• What is the purpose of transformers in power stations?

  To step up the voltage generated

  
• How does stepping up the voltage affect current in transmission lines?

  It reduces the current
• What is the relationship between current and heating effect in wires?

  Smaller currents have a smaller heating effect
• What is the equation for power loss in transmission lines?

  P = I R
• What does the equation P = I R indicate about power loss?

  Power loss is proportional to current
• What happens to power loss if the current is doubled?

  Power loss increases four times
• Why are step-up transformers used in transmission lines?

  To increase voltage and decrease current

  
• What is the function of a step-down transformer?

  To decrease voltage for homes and buildings

  
• How do you calculate power wasted in transmission lines?

  1. Identify known quantities:

  • Current, I = 2500 A
  • Length of cables, L = 150 km
  • Resistance of cables, R = 0.15 Ω/km

  1. Use power equation: P = I R
  2. Calculate total resistance: R = 0.15 × 150
  3. Substitute values into power equation
  4. Result: Power lost = 141 MW
• If the current is 2500 A and the resistance is 0.15 Ω/km over 150 km, what is the power wasted?

  141 MW
• What is the resistance of the transmission cable per kilometer?

  0.15 Ω/km
• What does the term "hysteresis loss" refer to in transformers?

  Energy loss due to magnetization changes
• What is the unit of power in the equation P = I R?

  Watts (W)
• What is the significance of using thick wires in transformers?

  To reduce resistance and energy loss