Question 1: Define a transformer in the context of magnetism and electrical energy transfer.

Answer: A transformer is a device that uses electromagnetic induction to change the voltage and current levels of alternating current electricity without changing its frequency.

Question 2: Explain the principle of electromagnetic induction that allows transformers to operate.

Answer: Transformers operate on the principle of electromagnetic induction, where a changing magnetic field induces an electric current in a coil of wire.

Question 3: What are the main components of a transformer?

Answer: The main components are two coils of wire called the primary and secondary coils, and a core made of iron or steel that concentrates the magnetic flux.

Question 1: A transformer has 500 turns in the primary coil and 50 turns in the secondary coil. If the primary voltage is 220 V, what is the voltage in the secondary coil? (Use the formula Vp/Vs = Np/Ns)

Answer: Vs = (Ns/Np) * Vp = (50/500) * 220 V = 0.1 * 220 V = 22 V

Question 2: A step-up transformer increases voltage from 120 V to 12,000 V. If the primary current is 3 A, what is the secondary current assuming ideal conditions? Use the formula Ip/Is = Ns/Np.

Answer: Is = (Np/Ns) * Ip = (12000/120) * 3 A = 100 * 3 A = 0.36 A

Question 1: Outline the main steps involved in assembling a basic transformer circuit for demonstration purposes.

Answer: First, obtain two coils of wire and a magnetic core. Wind the primary coil with insulated wire and connect it to an AC power source. Wind the secondary coil around the core. Ensure all connections are secure and insulated. Use appropriate safety gear. Check that the device is switched off before making adjustments. When powered, observe the voltage change across the secondary coil using a voltmeter.

Question 2: Identify three variables that can affect the efficiency of a transformer and explain their effects.

Answer: Core material quality (higher quality reduces energy loss), coil resistance (lower resistance reduces energy loss), and the number of turns in the coils (affects voltage and current ratios).

Question 3: List three safety precautions to consider when working with electrical transformers.

Answer: Ensure the device is unplugged before assembly, avoid contact with live wires, and use insulated tools and protective gear.

Question 1: A household transformer reduces the voltage from 240 V to 120 V to power home appliances. If the primary current is 0.5 A, what is the secondary current assuming ideal conditions? Explain your reasoning.

Answer: Using the ratio of voltages, the current ratio is inverse. So, Is = (Vp/Vs) * Ip = (240/120) * 0.5 A = 2 * 0.5 A = 1 A. This means the secondary current is 1 A. The transformer increases current while decreasing voltage proportionally.

Question 1: Describe how a transformer can be used in the electrical power distribution system to efficiently transmit electricity over long distances.

Answer: Transformers are used to step up the voltage at the generation station, which reduces current and energy loss during transmission. Near the consumption area, transformers step down the voltage to safe, usable levels for homes and businesses. This efficient voltage regulation minimizes energy loss and ensures safe delivery of electrical power.

Question 2: Explain why iron cores are used in transformers instead of air cores.

Answer: Iron cores are used because they have high magnetic permeability, which concentrates the magnetic flux, making the transformer more efficient at transferring energy compared to an air core.

Question 1: Identify one industry or technology that relies heavily on transformers and describe how they are used.

Answer: The electrical power industry relies on transformers to transmit high-voltage electricity over long distances and then step down the voltage for safe use in homes and businesses.

Question 2: How do transformers contribute to energy conservation in electrical systems?

Answer: Transformers reduce energy losses during transmission by allowing high-voltage, low-current transmission over long distances, and then reducing voltage for safe use, thus conserving energy.