Question 1: Define a transformer and explain its main function in electrical systems.

Answer: A transformer is an electrical device that changes the voltage level of alternating current electricity, typically increasing or decreasing voltage for efficient power transmission.

Question 2: What is the principle behind the operation of a transformer?

Answer: Transformers operate on the principle of electromagnetic induction, where a changing current in the primary coil induces a voltage in the secondary coil through a magnetic field.

Question 3: Describe the role of the core in a transformer.

Answer: The core concentrates the magnetic flux, enabling efficient transfer of energy between the primary and secondary coils.

Question 1: A transformer has 500 turns in the primary coil and 50 turns in the secondary coil. If the primary voltage is 240 V, what is the secondary voltage?

Answer: 24 V

Question 2: Using the previous problem, if the primary current is 2 A, what is the approximate primary current assuming an ideal transformer?

Answer: 20 A

Question 1: List three safety precautions to consider when working with high-voltage transformers.

Answer: Ensure proper insulation, avoid contact with live parts, and use appropriate personal protective equipment.

Question 2: Describe a simple experiment to demonstrate how a transformer transfers energy from one coil to another.

Answer: Use a primary coil connected to an AC power source and a secondary coil wrapped around the same core. When the primary coil is powered, a changing magnetic field induces a voltage in the secondary coil. Measuring the voltage in the secondary coil demonstrates energy transfer via electromagnetic induction.

Question 1: A power plant transmits electricity at 400,000 V through high-voltage transmission lines. Near the city, step-down transformers reduce the voltage to 230 V for household use. Explain how this process reduces energy loss during transmission.

Answer: Higher transmission voltages reduce current for the same power level, which decreases resistive energy losses (I^2R losses) in the transmission lines. Step-down transformers near consumers make the voltage suitable for household appliances, improving overall energy efficiency and reducing carbon emissions.

Question 1: Explain how the use of transformers in electrical grids contributes to combating climate change.

Answer: Transformers enable high-voltage transmission, which reduces energy losses over long distances. This efficiency reduces the amount of electricity wasted, leading to lower fossil fuel consumption and greenhouse gas emissions, thus helping combat climate change.

Question 2: A transformer has a power rating of 1500 VA. If the primary voltage is 120 V, what is the maximum secondary current, assuming ideal conditions?

Answer: 12.5 A

Question 1: Describe how modern smart transformers can improve energy efficiency and support renewable energy sources.

Answer: Smart transformers can dynamically adjust voltage levels, reduce energy losses, and integrate renewable sources like solar and wind into the grid more effectively, promoting sustainable energy use and reducing carbon emissions.