Chapter 9 Practice Paper: Magnetism — question paper

Section A: Multiple-choice questions[10 marks]

Choose the one correct answer for each question.

1. 1

   Which group contains only magnetic materials?

   1. Acopper, iron, steel
   2. Biron, nickel, cobalt
   3. Ccobalt, aluminium, steel
   4. Dnickel, copper, brass
   ( )
2. 2

   A plotting compass is placed close to the north pole of a bar magnet. The end of the needle nearest the magnet’s pole is

   1. Athe south-seeking end, attracted by the unlike pole
   2. Bthe north-seeking end, attracted by the like pole
   3. Cneither end, since the field is zero there
   4. Dwhichever end happens to swing there at random
   ( )
3. 3

   Magnetic field lines outside a bar magnet are drawn

   1. Afrom the south pole to the north pole
   2. Bcrossing each other near the poles
   3. Cfrom the north pole to the south pole
   4. Das closed circles around the middle of the magnet
   ( )
4. 4

   A steel needle is magnetised by the electrical method. Which arrangement works?

   1. Aplacing the needle inside a coil carrying direct current
   2. Bplacing the needle inside a coil carrying alternating current, then removing it from the coil
   3. Crubbing the needle with a copper rod
   4. Dheating the needle to 100 °C and letting it cool
   ( )
5. 5

   Electromagnet cores are made of soft iron rather than steel because soft iron

   1. Ais cheaper and heavier
   2. Bmagnetises and demagnetises easily
   3. Ccannot be magnetised at all
   4. Dconducts electricity better
   ( )

Section B: Structured questions[20 marks]

Answer all questions in the spaces provided.

1. 1

   Two identical-looking metal rods, P and Q, hang freely. The north pole of a bar magnet is brought near each end of each rod in turn: rod Q is attracted at both ends, while rod P is attracted at one end and repelled at the other.

   1. (a)

      Identify which rod is a magnet and justify the conclusion.

      [3]
   2. (b)

      State the pole type at the end of rod P that repelled the magnet’s north pole.

      pole =[1]
   3. (c)

      Explain why rod Q is attracted at both ends even though it is unmagnetised.

      [3]
2. 2

   A technician must demagnetise a steel screwdriver that keeps picking up loose screws, using only the equipment on the bench: a solenoid connected to an alternating-current supply, and a Bunsen burner.

   1. (a)

      Describe how the technician uses the solenoid and a.c. supply to demagnetise the screwdriver.

      [3]
   2. (b)

      Explain why the same coil connected to a direct-current supply would be the wrong choice here.

      [2]
   3. (c)

      State one other method of demagnetising the screwdriver and explain briefly why it works.

      [2]
3. 3

   A student maps the field around a bar magnet by placing a plotting compass near its north pole and marking the direction the compass needle points. The student repeats this at many points around the magnet.

   1. (a)

      State the direction of the magnetic field at a point, in terms of the compass needle.

      [2]
   2. (b)

      Describe the complete field pattern the student should draw around the bar magnet.

      [2]
   3. (c)

      State two properties of magnetic field lines shown by the completed map.

      [2]