Conceptual Questions

  1. Andre is flying his spaceship to the left through the laboratory magnetic field of FIGURE Q31.1.

    1. Does Andre see a magnetic field? If so, in which direction does it point?

    2. Does Andre see an electric field? If so, in which direction does it point?

    FIGURE Q31.1

    The figure illustrates a spaceship flying toward the left through a magnetic field.

  2. Sharon drives her rocket through the magnetic field of FIGURE Q31.2 traveling to the right at a speed of 1000 m/s as measured by Bill. As she passes Bill, she shoots a positive charge backward at a speed of 1000 m/s relative to her.

    1. According to Bill, what kind of force or forces act on the charge? In which directions? Explain.

    2. According to Sharon, what kind of force or forces act on the charge? In which directions? Explain.

    FIGURE Q31.2

    The figure illustrates a rocket and a positive charge in a magnetic field.

  3. If you curl the fingers of your right hand as shown, is the electric flux in FIGURE Q31.3 positive or negative?

    FIGURE Q31.3

    The figure illustrates curling of the fingers of the right hand in the counter-clockwise direction around a circle to find the polarity the electric flux. The electric field enclosed by the circle are marked by crosses.

  4. What is the current through surface S in FIGURE Q31.4 if you curl your right fingers in the direction of the arrow?

    FIGURE Q31.4

    The figure illustrates an inverted S-shaped surface inserted in a circular loop.

  5. Is the electric field strength in FIGURE Q31.5 increasing, decreasing, or not changing? Explain.

    FIGURE Q31.5

    The figure illustrates concentric circular arrow of induced magnetic field in an electric field.

  6. Do the situations in FIGURE Q31.6 represent possible electromagnetic waves? If not, why not?

    FIGURE Q31.6

    The figure consists of two parts labeled ("a") and (b) that illustrates a combination of electric field and magnetic field in a three-dimensional cartesian coordinate plane.

  7. In what directions are the electromagnetic waves traveling in FIGURE Q31.7?

    FIGURE Q31.7

    The figure labeled ("a") illustrates combinations of a magnetic field arrow and an electric field arrow.
    The figure labeled (b) illustrates combinations of a magnetic field and an Electric field arrow.

  8. The intensity of an electromagnetic wave is 10 W/m2. What will the intensity be if:

    1. The amplitude of the electric field is doubled?

    2. The amplitude of the magnetic field is doubled?

    3. The amplitudes of both the electric and the magnetic fields are doubled?

    4. The frequency is doubled?

  9. Older televisions used a loop antenna like the one in FIGURE Q31.9. How does this antenna work?

    FIGURE Q31.9

    A photograph of a loop antenna connected to a television.

  10. A vertically polarized electromagnetic wave passes through the five polarizers in FIGURE Q31.10. Rank in order, from largest to smallest, the transmitted intensities IA to IE.

    FIGURE Q31.10

    A photograph of five different polarizers. The polarizers are labeled "A", B, C, D, and E, from the left to the right. The polarizers are oriented at different angles.