Download 1. Object A has a charge of 2 nC, and object B has a charge of 6 nC

1. Object A has a charge of 2 nC, and object B has a charge of 6 nC.
Which statement is true about the electric forces on the objects?
(a) FAB = 3FBA
FAB = FBA
(b) FAB = FBA
(c) 3FAB = FBA
(d) FAB = 3FBA
(e)
(f) 3FAB = FBA
2. The electron and proton of a hydrogen atom are separated (on the average) by a distance of
approximately 5.3 10-11 m. Find the magnitudes of the electric force between the two
particles.
3. Two balls each having a charge of 3 μC are separated by 20 mm. What is the force of
repulsion between them?
4. Two point charges of -3 and +4 μC are 12 mm apart in a vacuum. What is the electrostatic
force between them?
5. What is the separation of two -4 μC charges if the force of repulsion between them is 200 N?
6. Two identical charges separated by 30 mm experience a repulsive force of 980 N. What is the
magnitude of each charge?
7. Three point charges lie along the x axis as shown in Figure. The positive charge q1 = 15.0 µC
is at x = 2.00 m, the positive charge q2 = 6.00 µC is at the origin, and the resultant force acting
on q3 is zero. What is the x coordinate of q3?
8. A test charge of 3 µC is at a point P where an external electric field is directed to the
right and has a magnitude of 4 106 N/C. If the test charge is replaced with another test
charge of - 3 µC, the external electric field at P .
(a) is unaffected
(b) reverses direction
(c) changes in a way
that cannot be determined
9. (a) Two identical conducting small spheres are placed with their centers 0.300 m
apart. One is given a charge of 12.0 nC and the other a charge of "18.0 nC. (a) Find the
electric force exerted by one sphere on the other.
(b) The spheres are connected by a conducting wire. Find the electric force between
the two after they have come to equilibrium.
10. (a) Find the potential at a distance of 1.00 cm from a proton.
(b) What is the potential difference between two points that are 1.00 cm and 2.00 cm from a
proton?
(c) What If? Repeat parts (a) and (b) for an electron.
11. Given two 2.00 C charges, and a positive test charge q =1.28 10-18 C at the origin,
(a) what is the net force exerted by the two 2.00
charges on the test charge q?
(b) What is the electric field at the origin due to the two 2.00 C charges?
(c) What is the electric potential at the origin due to the two 2.00 C charges?
12. Two conductors having net charges of 10.0 µC and -10.0 µC have a potential difference of
10.0 V between them.
(a) Determine the capacitance of the system.
(b) What is the potential difference between the two conductors if the charges on each are
increased to 100µC and -100 µC?
13. How much charge is on each plate of a 4.00µF capacitor when it is connected to a 12.0-V
battery?
(b) If this same capacitor is connected to a 1.50-V battery, what charge is stored?
14. Two capacitors, C1 = 5.00 µF and C2 = 12.0 µF, are connected in parallel, and the resulting
combination is connected to a 9.00-V battery.
(a) What is the equivalent capacitance of the combination?
(b) What is the potential difference across each capacitor and the charge stored on each
capacitor?
The two capacitors are now connected in series and to a 9.00-V battery.
Find:
(a) The equivalent capacitance of the combination.
(b) The potential difference across each capacitor.
(c) The charge on each capacitor.
15. Evaluate the equivalent capacitance of the configuration shown in Figure P26.18. All the
capacitors are identical, and each has capacitance C.
16. Two capacitors when connected in parallel give an equivalent capacitance of 9.00 pF and
give an equivalent capacitance of 2.00 pF when connected in series. What is the capacitance of
each capacitor?
17. Four capacitors are connected as shown in Figure.
(a) Find the equivalent capacitance between points a and b.
(b) Calculate the charge on each capacitorif !Vab # 15.0 V.
18. Three capacitors are connected to a battery as shown in Figure. Their capacitances are C1 =
3C, C2 = C, and C3 = 5C.
(a) What is the equivalent capacitance of this set of capacitors?
(b) State the ranking of the capacitors according to the charge they store, from largest to
smallest.
(c) Rank the capacitors according to the potential differences across them, from largest to
smallest.
(d) What If? If C3 is increased, what happens to the charge stored by each of the capacitors?
19. A 3.00µF capacitor is connected to a 12.0-V battery.
(a) How much energy is stored in the capacitor?
(b) If the capacitor had been connected to a 6.00-V battery, how much energy would have
been stored?
20. Two capacitors, C1 = 25.0 µF and C2 =5.00 µF, are connected in parallel and charged with a
100-V power supply.
(a) Draw a circuit diagram and calculate the total energy stored in the two capacitors.
(b) What If? What potential difference would be required across the same two capacitors
connected in series in order that the combination stores the same amount of energy as in
(a) Draw a circuit diagram of this circuit.
21. When resistors are connected in series, which of the following would be the same for each
resistor: potential difference, current, power?
22. When resistors are connected in parallel, which of the following would be the same for each
resistor: potential difference, current, power?
23. Calculate the total resistance (Req) between points a and b as shown in the figure
2Ω
2Ω
1Ω
3Ω
a
b
4Ω
24.
a- Find the equivalent resistance between points a and c.
b- What is the current in each resistor if a potential difference of 42 V is maintained
between a and c?
25. Three resistors are connected in parallel . A potential difference of 18.0 V is maintained
between points a and b.
a-
Find the current in each resistor
Calculate the power delivered to each resistor and the
b-
Calculate the total power delivered to the combination of resistors
c-
Calculate the equivalent resistance of the circuit.
26.
(a) Find the equivalent resistance between points a and b
(b) . (b) A potential difference of 34.0 V is applied between points a and b. Calculate the
current in each resistor.
27. Calculate the power delivered to each resistor in the circuit
28. The magnetic field is usually generated by moving charges
A False
B True
29. Moving electric charge generates
A only Electric field
B only magnetic field
C both electric field and magnetic field
30. The north magnetic pole of the earth is too the north geographic pole.
A False
B True
31. In a magnetic field B, a charge q moves with a velocity v in a direction making an angle θ
with B. Give the expression of the magnitude of F.
F = ………..
32. The magnetic force F is perpendicular :
A only to the velocity v
B only to the magnetic field B
33. Give the unit of the magnetic field and its symbol
C both to the velocity v and the magnetic field B
…………………………………………………………………………………………………………………..…………………………………………………………………………………………………………………..
34. A conductor wire with a length L carries an intensity of current I. The current is oriented by
an angle θ to the magnetic field B. Give the expression of the magnetic force magnitude on the
wire.
F = ………..
35. Draw the magnetic force in each case
B
I
B
I
A
I
B
B
C