Question 1: Define the term 'motor effect' in the context of electromagnetism.

Answer: The motor effect is the force experienced by a current-carrying conductor placed within a magnetic field, causing motion.

Question 2: Explain why a current-carrying wire in a magnetic field experiences a force that can cause it to rotate.

Answer: Because the magnetic force acts on the moving charges in the wire, producing a force perpendicular to both the magnetic field and current direction, resulting in a torque that causes rotation.

Question 3: Which direction does the force on a current-carrying conductor in a magnetic field depend on? List the rule used to determine this direction.

Answer: The force depends on the direction of the magnetic field, the current, and the force is determined using Fleming’s Left-Hand Rule.

Question 1: A wire of length 0.5 meters carrying a current of 3 amperes is placed in a magnetic field of flux density 0.2 Tesla. Calculate the force acting on the wire. (Use F = BIL sinθ, assume θ = 90° for maximum force)

Answer: 0.3 Newtons

Question 2: If the force on a conductor in a magnetic field is 2.5 N, the magnetic flux density is 0.4 T, and the length of the conductor is 0.75 m, what is the current passing through the conductor? (Use F = BIL sinθ, with θ = 90°)

Answer: 8.89 Amperes

Question 1: Describe a simple experiment to demonstrate the motor effect using a wire, a magnet, and a power supply. Include the variables you would control and measure, as well as safety precautions.

Answer: Set up a straight wire connected to a DC power supply within a uniform magnetic field created by a strong magnet. Control variables include the current magnitude and wire length. Measure the force or movement of the wire. Safety precautions include ensuring the circuit is off before adjusting connections, avoiding short circuits, and handling magnets carefully to prevent injury.

Question 1: A student measures the force on a wire in a magnetic field and finds it to be directly proportional to both the current and the length of the wire. Explain what this tells you about the relationship between these variables and the force.

Answer: It indicates that the force is directly proportional to both current and wire length, consistent with the formula F = BIL sinθ, confirming the linear relationship between force, current, and length.

Question 1: Describe how the motor effect is utilised in an electric fan. Include the role of magnetic fields and current in your explanation.

Answer: In an electric fan, current flows through coils within a magnetic field, producing a force that causes the coils to rotate, driving the blades. The motor effect converts electrical energy into mechanical energy to produce airflow.

Question 2: Explain why understanding the motor effect is important for designing efficient electric motors used in industry and transportation.

Answer: Understanding the motor effect allows engineers to optimise magnetic field strength, coil design, and current to maximise torque and efficiency. It also helps in reducing energy losses and improving the durability of motors used in various industrial and transportation applications.