2.5.1 Structure and Function

• What is the primary purpose of the National Grid?

  Distribute electricity
• Transformers are used in the National Grid to increase voltage for transmission and decrease it for local distribution.

  True
• What are the typical voltage levels of high-voltage transmission lines in the National Grid?

  275 kV or 400 kV
• High-voltage transmission allows efficient transport of electricity over large distances.


  True
• Steps in the use of transformers in the National Grid:

  1️⃣ Step-up transformers increase voltage from power stations

  2️⃣ High-voltage transmission lines carry electricity over long distances

  3️⃣ Step-down transformers decrease voltage for local use
• What type of transformer increases voltage in the National Grid?

  Step-up transformer
• Match the voltage level in the National Grid with its purpose:

  275 kV to 400 kV ↔️ Long-distance transmission

  11 kV to 33 kV ↔️ Distribution to substations

  230 V ↔️ Supply to homes and businesses
• Transformers ensure reliable electricity supply by regulating voltage levels across the National Grid.


  True
• Power stations in the National Grid are often located far from population centers
• What is the primary function of transformers in the National Grid?

  Change voltage levels
• Step-up transformers in the National Grid increase voltage to minimize energy losses
• In a step-up transformer, the secondary coil has fewer turns than the primary coil.

  False
• Step-down transformers reduce voltage from high-voltage lines to local distribution networks
• Distribution voltage in the National Grid ranges from 11 kV to 33 kV to supply electricity to city substations
• Substations use transformers to step down high-voltage electricity to 230 V for local use.


  True
• High-voltage transmission reduces energy loss by lowering the electrical current
• What is the function of a step-up transformer in the National Grid?

  Increase voltage for transmission
• Where are power stations often located in the National Grid?

  Far from population centers
• Transformers in the National Grid are used to change the voltage of electricity.

  True
• Step-down transformers reduce voltage from high to low
• Why is low voltage (230 V) used to supply homes and businesses?

  It is safe for direct use
• High-voltage transmission reduces energy loss by lowering the current in the lines.


  True
• What is the primary role of backup systems in the National Grid?

  Supply electricity in emergencies
• Monitoring and control systems in the National Grid track electricity flow in real-time.


  True
• The National Grid operates at high voltage to reduce energy loss
• Match the component of the National Grid with its description:

  Power Stations ↔️ Generate electricity far from cities

  High-Voltage Transmission Lines ↔️ Carry electricity long distances

  Transformers ↔️ Change voltage levels
• Local distribution networks deliver electricity to homes and businesses at 230 volts.
• What are transformers used for in the National Grid?

  Change voltage levels
• What type of transformer decreases voltage in the National Grid?

  Step-down transformer
• High-voltage transmission reduces current and energy loss in the National Grid.


  True
• Transformers in the National Grid increase voltage for transmission and decrease voltage for local distribution.
• What is the purpose of high-voltage transmission in the National Grid?

  Efficient transport of electricity
• High-voltage transmission lines in the National Grid operate at voltages of 275 kV or 400 kV.


  True
• Steps involved in the operation of a transformer

  1️⃣ AC electricity enters primary coil

  2️⃣ Magnetic field is created in iron core

  3️⃣ Secondary coil generates output voltage
• Match the transformer type with its function in the National Grid:

  Step-up transformer ↔️ Increases voltage from power stations

  Step-down transformer ↔️ Decreases voltage for local use
• What type of electricity is used in the National Grid?

  Alternating current (AC)
• What is the purpose of high voltage (275 kV to 400 kV) in the National Grid?

  Transporting electricity long distances
• Why is low voltage (230 V) used for homes and businesses in the National Grid?

  Safe for direct use
• What is the voltage level of high-voltage electricity in substations?

  275 kV to 400 kV
• Without high-voltage transmission, supplying electricity to remote areas would be impractical due to significant energy loss.

  True