PHYS  251      CHAPTER  22    QUIZ
PART  I      Multiple Choice
  1. * A positive ion has more
    A. electron than proton
    B. proton than electron
    C. electron than neutron
    D. neutron than electron
    E. none of the above
  2. * Strip electron from an atom and the atom becoms a
    A. negative ion
    B. different element
    C. neutral ion
    D. positive ion
    E. none of the above
  3. * A main difference between gravitational and electric forces is that electrical forces
    A. attract
    B. repel or attract
    C. obey the inverse square law
    D. act over short distances
    E. are weaker
  4. * To say that electric charge is quantized is to say that the charge on an object
    A. may occure in infinite variety of quantities
    B. is less than the actual efficiency
    C. will interact with neighboring electric charge
    D. is a whole number multiple of the charge of an electron
    E. none of the above
  5. * A difference between electric force and gravitational forces is that electrical forces include
    A. seperation distance
    B. repulsive interactions
    C. the inverse square law law
    D. infinite range
    E. none of the above


PART  II      Fill in Blanks
[NOTE : Make sure that your answers are in the dimensions shown]

6. The voltage between the cathode and the screen of a television set is 22kV.If an electron leaves the cathode with an initial speed of zero its speed just before it hits the screen is m/s
7. Starting from rest a proton falls through a p.d of 1200V The speed that it acquires is m/s
8. The electric force on a 2C charge is 60N The electric field at the place where the charge is located is N/C
9. Two charged particles attract each other with a force 20N. If the charges are doubled and the distance between them is doubled then the force of attraction will be N
10. Two charged particles repel each other with a force 20N. If the charges of one of the particle is doubled and the distance between them is doubled then the force will be N


PART  III     True  or  False
  1. The The electric force between charges is strongest when the charges are far apart.
    True
    False
  2. .A positive charg is enclosed in a hollow metallic sphere . At apoint directly above the hollow sphere the electric field caused by the enclosed positive charge has not changed
    True
    False
  3. A Electric charges of the same sign repel each other.
    True
    False
  4. A positive charge that is free to movebut is at rest in an electric field E experiences a force that is perpendicular to E.
    True
    False
  5. A proton is moving horizontally north in an Electric field pointed vertically upward. the force on the proton is upward.
    True
    False

Questions wrong