Sample Test MT1

Sample Test MT1
1. Object A has a charge q on it, object B has a charge q on it, and object C has a charge 2q on it. These
charges are arranged, one each, at the vertices of an equilateral triangle. Which charge has the greatest
magnitude electric force on it?
a. A
b. B
c. C
d. All have equal magnitude forces on them.
2.
Charges q, q, and –q are placed on the x-axis at x = 0, x = 2 m, and x = 4 m, respectively. At
which of the following points does the electric field have the greatest magnitude?
a. x = 1 m
b. x = 3 m
c. x = 5 m
d. The electric field has the same magnitude at all three positions.
3. A spherical surface surrounds a point charge it its center. If the charge is doubled and if the radius
of the surface is also doubled, what happens to the electric flux ΦE out of the surface and the
magnitude E of the electric field at the surface as a result of these doublings?
a. ΦE and E do not change.
b. ΦE increases and E remains the same.
c. ΦE increases and E decreases.
d. ΦE increases and E increases.
4. A repelling force must occur between two charged objects under which conditions?
a. Charges are of unlike signs.
b. Charges are of like signs.
c. Charges are of equal magnitude.
d. Charges are of unequal magnitude.
5. If body M, with a positive charge, is used to charge body N by induction, what will be the nature
of the charge left on the latter?
a. must be equal in magnitude to that on M
b. must be negative
c. must be positive
d. must be greater in magnitude than that on M
6 Two point charges are 4 cm apart. They are moved to a new separation of 2 cm. By what factor does
the resulting mutual force between them change?
a. 1/2
b. 2
c. 1/4
d. 4
7. In a thundercloud there may be an electric charge of +40 C near the top of the cloud and 40 C
near the bottom of the cloud. These charges are separated by about 2.0 km. What is the electric
force between these two sets of charges? (ke = 8.99  109 N·m2/C2)
a. 3.6  104 N
b. 3.6  105 N
c. 3.6  106 N
d. 3.6  107 N
8, Relative distribution of charge density on the surface of a conducting solid depends on:
a. the shape of the conductor.
b. mass density of the conductor.
c. type of metal of which the conductor is made.
d. strength of the earth's gravitational field.
9. Three capacitors have capacitances C1 < C2 < C3. If these capacitors are connected in series, which of
the following is true for the resulting equivalent capacitance?
a. Ceq < C1
b. Ceq > C3
c. Ceq = (C1 + C2 + C3)/3
d. None of the above is always correct.
10. A 9.0-V battery is connected between two parallel metal plates 4.0 mm apart. What is the magnitude
of the electric field between the plates?
a. 2.3  103 N/C
b. 9.0 N/C
c. 2.3 N/C
d. 0.75  106 N/C
11. If the distance between two isolated parallel plates that are oppositely charged is doubled, the electric
field between the plates is essentially unchanged. However, the:
a. potential difference between the plates will double.
b. charge on each plate will double.
c. force on a charged particle halfway between the plates will get twice as small.
d. force on a charged particle halfway between the plates will get four times as small.
12. What is the equivalent capacitance between points a and b? All capacitors are 1.0 F.
a. 4.0 µF
b. 1 7 µF
c. 0.60 µF
d. 0.25 µF
13. A wire has resistance R. A second wire has twice the length, twice the diameter, and twice the
resistivity of the first wire. What is its resistance?
a. 8 R
b. R
c. R/4
d. The resistance is not given.
14. The size of the electric current in a electrical conductor is a function of which of the following?
a. velocity of charge carriers
b. conductor cross sectional area
c. density of charge carriers
d. All of the above choices are valid.
15. A resistor is connected to a battery with negligible internal resistance. If you replace the resistor with
one that has twice the resistance, by what factor does the power dissipated in the circuit change?
a. 0.50
b. 0.25
c. 4.0
d. 2.0
16. Kirchhoff’s rules are the junction rule and the loop rule. Which of the following statements is true?
a. Both rules are based on the conservation of charge.
b. Both rules are based on the conservation of energy.
c. The junction rule is based on the conservation of charge, and the loop rule is based on
the conservation of energy.
d. The junction rule is based on the conservation of energy, and the loop rule is based on
the conservation of charge.
17. Three resistors connected in series each carry currents labeled I1, I2 and I3. Which of the following
expresses the value of the total current IT in the system made up of the three resistors in series?
a. IT = I1 + I2 + I3
b. IT = (1/I1 + 1/I2 + 1/I3)
c. IT = I1 = I2 = I3
d. IT = (1/I1 + 1/I2 + 1/I3)1
18. Consider the circuit shown in the figure. What power is dissipated by the entire circuit?
a. 14 W
b. 28 W
c. 52 W
d. 112 W
19. What is the current through the 8- resistor?
a. 1.0 A
b. 0.50 A
c. 1.5 A
d. 2.0 A