Question 1: Explain how an electromagnet produces a magnetic field when an electric current flows through a coil of wire.

Answer: An electromagnet produces a magnetic field because the electric current flowing through the coil of wire creates a magnetic field around the wire, following right-hand rule principles.

Question 2: Which material is commonly used as the core in an electromagnet to increase its magnetic strength? A) Copper B) Iron C) Aluminium D) Sulphur

Answer: Iron

Question 3: Fill in the blank: Increasing the number of __________ turns in the coil will generally increase the magnetic field strength of an electromagnet.

Answer: turns

Question 1: Calculate the magnetic field strength (B) at the centre of a solenoid of length 0.5 m, with 200 turns, carrying a current of 3 A. Use the formula B = μ₀ * (N/L) * I, where μ₀ = 4π × 10⁻⁷ T·m/A.

Answer: B = 4π × 10⁻⁷ * (200 / 0.5) * 3 = 1.51 × 10⁻³ T

Question 2: A student increases the number of turns in their electromagnet from 150 to 300 while keeping the length and current constant. By what factor does the magnetic field strength increase?

Answer: The magnetic field strength doubles (factor of 2).

Question 1: Describe a simple experiment to investigate how the number of turns in a coil affects the strength of an electromagnet. Include variables you would control and safety precautions.

Answer: Set up a coil with a variable number of turns around a soft iron core connected to a power supply. Use a magnetic compass to measure the magnetic strength for different numbers of turns. Control variables such as current, coil length, and core material. Ensure the power supply is handled safely, avoid short circuits, and do not overload the circuit.

Question 2: What safety precautions should be taken when working with electromagnets in a laboratory setting?

Answer: Ensure the power supply is turned off when adjusting the circuit, avoid touching hot wires or components, use insulated wires, and do not exceed recommended current limits to prevent overheating.

Question 1: A series of measurements shows that increasing the current through an electromagnet from 1 A to 3 A doubles the magnetic field strength. Explain why this occurs, referencing the relevant physics principles.

Answer: The magnetic field strength is directly proportional to the current flowing through the coil, according to the formula B = μ₀ * (N/L) * I. Therefore, increasing current increases the magnetic field proportionally.

Question 1: Name an industry or technology that relies heavily on electromagnets and briefly describe how they are used.

Answer: Electrocardiograms (ECGs) use electromagnets to detect and record electrical signals from the heart, enabling medical diagnosis.

Question 2: Explain one advantage of using electromagnets over permanent magnets in industrial lifting equipment.

Answer: Electromagnets can be switched on and off quickly, allowing precise control over lifting and releasing heavy metallic objects, which is not possible with permanent magnets.