問題一覧
1
What is the voltage of a battery connected to a parallel plate capacitor with a plate area of 2.0 cm2 and a plate separation of 2 mm if the charge stored on the plates is 4.0 pC?
4.5V
2
As a proton moves in the direction the electric field lines...
it is moving from high potential to low potential and losing electric potential energy.
3
The unit Volt, V is the same as.
J/C
4
A negative charge moves in the direction of a uniform electric field. What does this entail?
The potential cannot be determined.
5
2. Which of the following is the most effective conductor?
iron
6
What is the direction of the electric field at the test point on the -x-axis, 50 cm from the charge q = -5.00 nC which is located at the origin?
westward
7
What is the potential difference VA-VB?
45,000 V
8
If a parallel plate capacitor of plate area 2 m2 and plate separation of 1 m stores the charge of 1.77 x 10-11 C, what is the voltage across the capacitor?
1V
9
20V
10
When moving from infinity to towards a negative point charge, the electric potential.
decreases
11
Two like charges of charge +10 nC are placed at the two corners of an equilateral triangle of side 3 cm. What is the magnitude of the total potential at the third corner?
6000 V
12
. A typical capacitor in a memory cell have a capacitance of 3 x 10-14 F. If the voltage across the capacitor is 0.5 V, what is the number of electrons that must move to the capacitor to charge it?
93750
13
A system of two charges has a negative potential energy. This signifies that
one charge is positive & the other is negative
14
9. A potential difference of 100 mV exists between the outer and inner surfaces of a cell membrane. The inner surface is negative relative to the outer. How much work is required to move a sodium ion Na+ outside the cell from the interior? (Express your answer in electron volts. A singly-charged ion has a charge of A eV, 1 eV = 1.6 × 10−19 J.
0.1 eV
15
. A positive charge is located at the origin. As a test charge moves away from the charge, what will happen to the electric potential electric potential due to this charge?
decreases
16
Capacitor stores which type of energy?
potential energy
17
Why does capacitor block dc signal at steady state?
due to zero frequency of dc signal
18
. Of the following quantities, which is vector in character?
electric field
19
Refer to the diagram in item number 5. What is the voltage across C4? A) B) C) D)
5V
20
A charge of 31μC moves from the positive to the negative terminal of a 9.0-V battery. How much energy does the battery impart to the charge?
2.79x10-4 J
21
Which of the following statements are TRUE? I. When a positive charge moves in the direction of an electric field, the field does negative work and the potential energy increases. II. When a negative charge moves in the direction of an electric field, the field does negative work and the potential energy increases. III. When a negative charge moves in the direction of an electric field, the field does positive work and the potential energy decreases.D. D.
B. II&III
22
Why does capacitor block dc signal at steady state?
Due to zero frequency of dc signal.
23
Which of the following is TRUE about electric charge? .
It can be transferred from atom to atom
24
The electric potential energy due to several point charges is given by the equation: U = k Σ qi / r2 i. The r indicates:
the distance from the point charge to the point at which the potential energy is evaluated.
25
What is the energy per unit charge?
voltage
26
An electron traveling horizontally from North to South enters a region where a uniform electric field is directed downward. What is the direction of the electric force exerted on the electron once it has entered the field?
upward
27
What is the magnitude of the net electric field at (+1.0 m, 0) due to the three charges in number 9?
297, 348 N/C
28
Which of the following refers to the function of a capacitor?
It absorbs and stores electrical charge.
29
. What is the electric field strength at a point 50 cm from a charge q = + 5.00 nC?
180 N/C
30
Capacitor stores which type of energy?
potential energy
31
A parallel-plate capacitor has 4.00 cm2 plates separated by 6.00 mm of air. If a 12.0V battery is connected to this capacitor, how much energy does it store in Joules?
4.25 × 10-11 J
32
Which of the following is the least effective conductor?
oil
33
The magnitude of electric potential is ______ at an infinite distance.
zero
34
What is the value of capacitance of a capacitor which has a voltage of 4V and has 16C of charge?
4F
35
The electric potential due to several point charges is given by the equation: V = kΣqi / ri. The r indicates:
the distance from the point charge to the point at which the potential is evaluated
36
The electric field has a magnitude of 3.0 N/C at a distance of 30 cm from a point charge. What is the charge?
1.4 nC
37
What is the potential at point A?
-180,000 V
38
Which of the following is FALSE?
A static charge never produces an electric field.
39
Two protons in the nucleus of a 238U atom are 6.0 fm (6.0x10-15m) apart. What is the potential energy (in joules) associated with the electric force that acts between these two particles? A. B.C.D.
3.8x10-14
40
. Three point charges are located on the x-axis. The first charge, q1 = +10 µC, is at x = -1.0 m. The second charge, q2 = +20 µC, is at the origin. The third charge, q3 = - 30 µC, is located at x = +2.0 m. What is the net force on q2?
3.15 N to the positive x- direction
41
Which of the following statements are TRUE? I. When a positive charge moves in the direction of an electric field, the potential energy decreases and the field does positive work II. When a positive charge moves in the direction of an electric field, the potential energy increases and the field does negative work III. When a negative charge moves in the direction of an electric field, the potential energy increases and the field does negative work IV. When a negative charge moves in the direction of an electric field, the potential energy decreases and the field does positive work
I &III
42
An electron & a proton are accelerated through the same potential difference
the proton has lower speed.
43
Two point charges are arranged along the x-axis; q1=2.0 µC is at x=0.80m, and q2=2.0 µC at x=0.80m . The net electrical potential measured at the origin due to these point charges is
45kV
44
Of the following quantities, the one that is not a scalar in character is
electric field
45
It is the unit of capacitance.
Farad
46
A point charge q = 2.00μC is located at the origin. Find the electric potential due to this charge at point x = 4.0 m.
4500 V
47
Which of the following is a passive device?
Capacitor
48
14. What is the potential at point B?
-225,000 V
49
A system of two charges has a positive potential energy. This closely indicates that
both charges are positive
50
How is the direction of the electric field lines related to the equipotential surface?
perpendicular
51
In terms of energy unit, which does not belong? A. B. C. D.
V
52
How much work is done in moving a charge between two points on the same equipotential surface?
zero
53
Of which medium is capacitance high? A) B) C) D)
Mica
54
Which statements must be true about the surface of a charged conductor in which no charge is moving?
The electric potential is constant over the surface.
55
A 1.65 nC charge with a mass of 1.5 x 10-15 kg experiences an acceleration of 6.33 x 107 m/s2 in an electric field. What is the magnitude of the electric field?
57.55 N/C
56
Electric potential ____________ as distance increases.
decreases