1. Two permanent magnets are placed close together. They begin to push away from each other. Which is true?
    A) Both magnets have the same pole facing each other
    B) One magnet is north and the other is south
    C) The magnets have the same strength
    D) The field lines are crossing

  2. A transformer changes the alternating voltage. If the secondary voltage is higher than the primary voltage, what is the turn ratio?
    A) Ns > Np
    B) Np > Ns
    C) Np = Ns
    D) The transformer does not work

  3. A coil of wire is connected to a battery and connected to a light bulb. If the switch is opened, what happens?
    A) The magnetic field around the coil disappears immediately
    B) The field lines continue to circulate
    C) The bulb stays lit for a few seconds
    D) The induced voltage becomes zero

  4. A step-up transformer has V_p = 20 V, N_p = 500, N_s = 2500. Find the secondary voltage V_s.

  5. A step-down transformer has a primary voltage V_p = 230 V and 500 turns. What is the secondary voltage V_s if N_s = 250?

  6. Describe Fleming’s Left-Hand Rule. How are the thumb, first finger, and second finger used to determine the direction of force, magnetic field, and current?

  7. Why do transformers not work with direct current (d.c.)? Explain the mechanism.

  8. List three ways to increase the strength of a solenoid’s magnetic field.

  9. Why is high-voltage transmission used in the power grid?

  10. Why are slip rings used in a.c. generators instead of a split-ring commutator? Why is a split-ring commutator used in d.c. motors instead of slip rings?

Attempt the quiz before checking the mark scheme
Mark Scheme P7 - Magnetism and Electromagnetism Mark Scheme
Topic guide: P7 - Magnetism and Electromagnetism