B.  Conductors On-line quiz

15 points each question

300 points total

 

31. The dielectric constant has dimensions of:

    a. N/C

    b.    Farad

    c.    volts

    d. eV

    e.    dimensionless

 

32.   Electric potential has units of:

    a. N/C

    b.    Farad

    c.    volts

    d. eV

    e.    dimensionless

 

33.   Capacitance has units of:

    a. N/C

    b.    Farad

    c.    volts

    d. eV

    e.    dimensionless

 

34.   Electric Potential Energy may be expressed in units of:

    a. N/C

    b.    Farad

    c.    volts

    d. eV

    e.    dimensionless

 

35.   Capacitance is ÷o A/d for:

    a. all capacitors

    b.    concentric cylinders

    c.    parallel plates

    d.    parallel wires

 

36. Given 3 capacitors: 4.00 mF, 7.00 mF, and 9.00 mF; what is the equivalent capacity if they are connected in series?

    a.  1.98 mF    b.  3.00 mF     c.  2.98 mF   d.  5.00 mF

 

37. Given 3 capacitors: 4.00 mF, 7.00 mF, and 9.00 mF; what is the equivalent capacity if they are connected in parallel?

     a.  22.00 mF    b.  20.00 mF   c.  6.75 mF   d.  3.25 mF


Page 2

 

38.   Consider a uniform electric field of 50 N/C directed toward the east.  If the voltage measured relative to ground at a given point in the field is 80 V, what is the voltage at a point 1 m directly south of that point?

    a.    zero

    b. 30 V

    c. 50 V

    d. 80 V

 

39. The absolute potential at a distance of 2 m from a positive point charge is 100 V.  What is the absolute potential 4 m away from the same point charge?

    a. 25 V

    b. 50 V

    c. 200 V

    d. 400 V

 

40. A battery charges a parallel-plate capacitor fully and then is removed.  The plates are immediately pulled apart.  (With the battery disconnected, the amount of charge on the plates remains constant.)  What happens to the potential difference between the plates as they are being separated?

    a. It increases.

    b. It decreases.

    c. It remains constant.

    d.    There is no way to tell from the information given.

 

41. The plates of a parallel-plate capacitor are maintained with constant voltage by a battery as they are pulled apart.  During this process, the amount of charge on the plates must

    a.    increase.

    b.    decrease.

    c.    remain constant.

    d.    either increase or decrease.  There is no way to tell from the information given.

 

42. The plates of a parallel-plate capacitor are maintained with constant voltage by a battery as they are pulled apart.  What happens to the strength of the electric field during this process?

    a. It increases.

    b. It decreases.

    c. It remains constant.

    d.    There is no way to tell from the information given.

 


Page 3

 

43. If a Cu2+ ion drops through a potential difference of 12 V, it will acquire a kinetic energy (in the absence of friction) of

    a. 12 eV

    b. 6 eV

    c. 24 eV

    d.    none of the above.

 

44. The electron-volt is a unit of

    a.    voltage.

    b.    current.

    c.    power.

    d.    energy.

 

45. A 15-mF capacitor is connected to a 50-V battery and becomes fully charged.  The battery is removed and a slab of dielectric that completely fills the space between the plates is inserted.  If the dielectric has a dielectric constant of 5, what is the capacitance of the capacitor after the slab is inserted?

    a. 75 mF

    b. 20 mF

    c. 3 mF

    d.    None of the above

 

46. A 15-mF capacitor is connected to a 50-V battery and becomes fully charged.  The battery is removed and a slab of dielectric that completely fills the space between the plates is inserted.  If the dielectric has a dielectric constant of 5, what is the voltage across the capacitor's plates after the slab is inserted?

    a. 250 V

    b. 10 V

    c. 2 V

    d.    None of the above

 

47.   Capacitors connected in series always have ____ total capacitance than any of the individual capacities.

a) more

b) less

 

48. An electron moving from the negative terminal to the positive terminal of a 12. volt battery gains (or loses) how much energy?  Be sure to indicate whether it is a gain or loss.

  a.  gains 12.eV (1.9ð10-19 J)

  b.  Loses 15.eV (1.9ð10-19 J)

  c.  Loses 12.eV (1.9ð10-19 J)

  d.  gains 15.eV (1.9ð10-19 J)

49. An electron volt is a unit of:

    a.    potential

    b.    charge

    c.    voltage

    d.    energy

 

50. A negative charge, if free, tries to move

    a.    from high potential to low potential

    b.    from low potential to high potential

    c.    toward infinity

    d.    away from infinity