A technician discovers that a steel screwdriver has become strongly magnetised, interfering with delicate electronic components. The technician needs to demagnetise the screwdriver. Which of the following describes the most effective method to demagnetise the screwdriver?
Place the screwdriver inside a solenoid carrying a large alternating current (a.c.) and then slowly withdraw it far away from the solenoid along its axis.
Place the screwdriver inside a solenoid carrying a large direct current (d.c.) and then slowly withdraw it.
Connect the ends of the screwdriver directly to an alternating current (a.c.) power supply.
Strike the screwdriver repeatedly with a hammer while keeping it aligned in a North-South direction.
169 exam-style questions on CIE IGCSE Physics Simple phenomena of magnetism, covering Simple phenomena of magnetism. Each one has a worked solution and a mark scheme showing where the marks go.