Question 1: Explain the principle of how a transformer works based on the generator effect.

Answer: A transformer operates on the principle of electromagnetic induction, where a changing current in the primary coil creates a changing magnetic field that induces a voltage in the secondary coil. This process allows voltage to be increased or decreased depending on the number of turns in the coils.

Question 1: Define what a transformer is.

Answer: A transformer is an electrical device that changes the voltage of alternating current using electromagnetic induction between two coils.

Question 2: What is the purpose of the number of turns in the primary and secondary coils?

Answer: The number of turns determines whether the transformer increases (step-up) or decreases (step-down) voltage. More turns on the secondary coil compared to the primary increases voltage, and vice versa.

Question 1: A transformer has 200 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: 60 V

Question 2: Calculate the turns ratio if a transformer steps down voltage from 1200 V to 240 V.

Answer: N_s / N_p = 0.2

Question 1: Describe a simple experiment to demonstrate electromagnetic induction using a transformer.

Answer: One could set up a primary coil connected to an AC power supply and a secondary coil connected to a galvanometer. When the current in the primary coil is switched on and off, the changing magnetic field induces a current in the secondary coil, which can be detected by the galvanometer. Safety precautions include ensuring proper insulation, avoiding contact with live wires, and confirming the transformer is rated for the voltage used.

Question 2: Identify three safety precautions to observe when working with transformers.

Answer: Ensure proper insulation of wires, avoid touching live components, and use transformers within their rated voltage and current limits.

Question 1: A household transformer reduces the main supply voltage of 230 V to 12 V for a doorbell. If the secondary coil has 10 turns, how many turns does the primary coil have?

Answer: Approximately 192 turns

Question 1: Explain how step-up transformers are used in the generation of electricity at power stations.

Answer: Step-up transformers increase the voltage produced by generators to high levels for efficient long-distance transmission, reducing energy loss during transmission.

Question 2: Identify a day-to-day device that uses a transformer and describe its function.

Answer: A phone charger uses a transformer to convert high-voltage mains electricity to a low voltage suitable for charging the phone's battery.