Question 1

The electric field due to a uniform distribution of charge on a spherical shell is zero:
A)everywhere
B)nowhere
C)only at the center of the shell
D)only inside the shell
E)only outside the shell

Accepted Answer

The electric field due to a uniform distribution of charge on a spherical shell is zero only inside the shell, according to Gauss's law. This is because the electric field lines do not penetrate into the enclosed space, effectively canceling out any net electric field within the shell.

Question 2

A 200-N/C electric field is in the positive x direction.The force on an electron in this field is: A)200 N in the positive x direction B)200 N in the negative x direction C)3.2 *10^-17 N, in the positive x direction D)3.2 * 10^-17 N, in the negative x direction E)0 N

Accepted Answer

The force on an electron in an electric field is given by the equation F = qE, where F is the force, q is the charge of the particle, and E is the electric field strength. In this case, the charge of the electron is negative and the electric field is in the positive x direction. Therefore, the force on the electron is in the negative x direction, and its magnitude is given by F = (1.6 x 10^-19 C)(200 N/C) = 3.2 x 10^-17 N. So, the correct answer is D.

Question 3

Charge is placed on the surface of a 2.7-cm radius isolated conducting sphere.The surface charge density is uniform and has the value 6.9 * 10^-6 C/m².The total charge on the sphere is: A)5.7 * 10^-10 C B)1.6 * 10^-8 C C)3.2 *10^-8 C D)6.3 * 10^-8 C E)7.5 *10^-⁴ C

Accepted Answer

The total charge Q on the sphere can be found by multiplying the surface charge density σ by the surface area A of the sphere:
Q = σA
The surface area of a sphere is given by the formula 4πr^2, where r is the radius of the sphere. Substituting the given values:
Q = (6.9×10^-6 C/m^2)×(4π×(0.027 m)^2) = 6.27×10^-8 C
Therefore, the answer is D, 6.3×10^-8 C.

Question 4

A total charge of 6.3 *10^-8 C is distributed uniformly throughout a 2.7-cm radius sphere.The volume charge density is: A)3.7 *10^-7 C/m³ B)6.9*10^-6 C/m³ C)6.9 *10^-6 C/m² D)2.5 * 10^-4 C/m³ E)7.6 * 10^-4 C/m³

Accepted Answer

The answer of A total charge of 6.3 *10^-8 C...

Question 5

Comparing the field of a single point charge with the field of an electric dipole,
A)the field of the point charge decreases more rapidly with distance
B)the field of the point charge decreases less rapidly with distance
C)the field of the point charge decreases more rapidly with distance but only along the dipole axis
D)the field of the point charge decreases less rapidly with distance but only perpendicular to the dipole axis
E)the fields decrease equally rapidly with distance

Accepted Answer

The field of a single point charge decreases as the inverse square of the distance from the charge (1/r^2), whereas the field of an electric dipole decreases more rapidly, as the inverse cube of the distance from the dipole's center (1/r^3) along any direction. Therefore, the field of the point charge decreases less rapidly with distance compared to the dipole field.

Question 6

A cylinder has a radius of 2.1 cm and a length of 8.8 cm.Total charge 6.1 * 10^-7 C is distributed uniformly throughout.The volume charge density is: A)7.4 * 10^-11 C/m³ B)5.3*10^-5 C/m³ C)5.3* 10^-5 C/m² D)8.5 *10^-4 C/m³ E)5.0* 10^-3 C/m³

Accepted Answer

The answer of A cylinder has a radius of 2.1...

Question 7

An electron traveling north enters a region where the electric field is uniform and points north.The electron:
A)speeds up
B)slows down
C)veers east
D)veers west
E)continues with the same speed in the same direction

Accepted Answer

The electric field is pointing in the same direction that the electron is traveling, which means that the field is doing work in the same direction as the electron's velocity. This work adds energy to the electron, causing it to speed up initially. However, as the electron accelerates, it experiences an increase in resistance from the surrounding medium (air, for example), which causes it to slow down.

Question 8

An electric dipole consists of two charges, ±2.5 µC, separated by 1.0 x 10^-4 m and centered on the origin.If the dipole is oriented along the x axis, what is the electric field at x = 15 cm? A)0 N/C B)100 N/C C)200 N/C D)670 N/C E)1300 N/C

Accepted Answer

The answer of An electric dipole consists of two charges,...

Question 9

A charged particle is placed in an electric field that varies with location.No force is exerted on this charge: A)at locations where the electric field is zero B)at locations where the electric field strength is 1/(1.6 * 10^-19)N/C C)if the particle is moving along a field line D)if the particle is moving perpendicular to a field line E)if the field is caused by an equal amount of positive and negative charge

Accepted Answer

A charged particle placed in an electric field experiences a force given by F=qE, where q is the charge of the particle and E is the electric field strength. Therefore, if the electric field strength is zero (option A), the particle will not experience any force and will remain stationary. Option B gives a specific value of electric field strength, which may or may not be zero depending on the situation. Option C is incorrect because the particle's motion along a field line does not necessarily mean that it will not experience a force. Option D is also incorrect because if the particle is moving perpendicular to a field line, it will experience a force that is perpendicular to its velocity, resulting in curvilinear motion. Option E is also incorrect because the net effect of a combination of positive and negative charges is the electric field that is produced. If the electric field strength at a point is zero, it means that the net effect of the positive and negative charges cancel each other out at that point.

Question 10

Two point charges are arranged as shown.In which region could a third charge +1 C be placed so that the net electrostatic force on it is zero? 
A)I only
B)I and II only
C)III only
D)I and III only
E)II only

Accepted Answer

The answer of Two point charges are arranged as shown.In...

Question 11

The diagram shows two identical particles, each with positive charge Q.The electric field at point P on the perpendicular bisector of the line joining them is: 
A)"$\uparrow$"
B)"$\downarrow$"
C)"$\rightarrow$"
D)"$\leftarrow$"
E)"zero"

Accepted Answer

The answer of The diagram shows two identical particles, each...

Question 12

A spherical shell has an inner radius of 3.7 cm and an outer radius of 4.5 cm.If charge is distributed uniformly throughout the shell with a volume density of 6.1*10^-4 C/m³ the total charge is: A)1.0*10^-7 C B)1.3*10^-7 C C)2.0 * 10^-7 C D)1.7* 10^-⁶ C E)5.0 *10^-⁶ C

Accepted Answer

The answer of A spherical shell has an inner radius...

Question 13

An electric dipole consists of a particle with a charge of +6 * 10^-6 C at the origin and a particle with a charge of -6* 10^-6 C on the x axis at x = 3 * 10^-3 m.The direction of the electric field due to the dipole at points on the x axis is: A)in the positive x direction B)in the negative x direction C)in the positive y direction D)in the negative y direction E)in the positive x direction between the charges and in the negative x direction elsewhere

Accepted Answer

The electric field due to a dipole on the x axis is along the axis itself, and points towards the negative charge. Therefore, between the two charges, the electric field will be in the positive x direction and outside the charges, it will be in the negative x direction. Thus, the correct answer is E.

Question 14

Two point particles, one with charge +8 *10^-9 C and the other with charge-2 *10^-9 C, are separated by 4 m.The electric field midway between them is: A)9 *10⁹N/C B)13,500 N/C C)135,000 N/C D)36 *10^-9N/C E)22.5 N/C

Accepted Answer

The answer of Two point particles, one with charge +8...

Question 15

Two charged point particles are located at two vertices of an equilateral triangle and the electric field is zero at the third vertex.We conclude:
A)the two particles have charges with opposite signs and the same magnitude
B)the two particles have charges with opposite signs and different magnitudes
C)the two particles have identical charges
D)the two particles have charges with the same sign but different magnitudes
E)at least one other charged particle is present

Accepted Answer

The answer of Two charged point particles are located at...

Question 16

A disk with a uniform positive surface charge density lies in the x-y plane, centered on the origin.The disk contains 2.5 x 10^-6 C/m² of charge, and is 7.5 cm in radius.What is the electric field at z = 15 cm? A)30 N/C B)300 N/C C)3000 N/C D)3.0 x 10⁴ N/C E)3.0 x 10⁷ N/C

Accepted Answer

The answer of A disk with a uniform positive surface...

Question 17

Two point particles, with the same charge, are located at two vertices of an equilateral triangle.A third charged particle is placed so the electric field at the third vertex is zero.The third particle must:
A)be on the perpendicular bisector of the line joining the first two charges
B)be on the line joining the first two charges
C)be identical to the first two charges
D)have the same magnitude as the first two charges but may have a different sign
E)be at the center of the triangle

Accepted Answer

The answer of Two point particles, with the same charge,...

Question 18

The magnitude of the force of a 400-N/C electric field on a 0.02-C point charge is: A)8 N B)5 * 10^-5 N C)8 * 10^-3 N D)0.08 N E)2 * 10³ N

Accepted Answer

The force on a charge in an electric field is given by F = qE, where q is the charge (0.02 C) and E is the electric field strength (400 N/C). Thus, F = 0.02 C * 400 N/C = 8 N.

Question 19

An electric dipole consists of a particle with a charge of +6 * 10^-6 C at the origin and a particle with a charge of -6*10^-6 C on the x axis at x = 3 * 10^-3 m.Its dipole moment is: A)1.8 * 10^-8 C.m, in the positive x direction B)1.8 *10^-8 C.m, in the negative x direction C)0 C.m, because the net charge is 0 D)1.8 * 10^-8 C.m, in the positive y direction E)1.8 *10^-8 C.m, in the negative y direction

Accepted Answer

The answer of An electric dipole consists of a particle...

Question 20

A disk with a uniform positive surface charge density lies in the x-y plane, centered on the origin.Along the positive z axis, the direction of the electric field is:
A)in the +z direction
B)in the -z direction
C)in the +x direction
D)in the +y direction
E)there is no field along the positive z axis

Accepted Answer

According to Gauss's Law, the electric field due to a uniformly charged disk at a point along the axis passing through its center is given by 
E = (σ/2ε0)(1/(1+(z/R)^2)^1.5)
where σ is the surface charge density of the disk, ε0 is the permittivity of free space, z is the distance of the point from the center of the disk along the axis passing through it and R is the radius of the disk. 
Note that the electric field due to the disk is pointing in the direction of z-axis only. Hence, the electric field at a point along the positive z-axis will be in the +z direction.

Quiz 22: Electric Fields

The electric field due to a uniform distribution of charge on a spherical shell is zero:

A 200-N/C electric field is in the positive x direction.The force on an electron in this field is:

Charge is placed on the surface of a 2.7-cm radius isolated conducting sphere.The surface charge density is uniform and has the value 6.9 * 10^-6 C/m².The total charge on the sphere is:

A total charge of 6.3 *10^-8 C is distributed uniformly throughout a 2.7-cm radius sphere.The volume charge density is:

Comparing the field of a single point charge with the field of an electric dipole,

A cylinder has a radius of 2.1 cm and a length of 8.8 cm.Total charge 6.1 * 10^-7 C is distributed uniformly throughout.The volume charge density is:

An electron traveling north enters a region where the electric field is uniform and points north.The electron:

An electric dipole consists of two charges, ±2.5 µC, separated by 1.0 x 10^-4 m and centered on the origin.If the dipole is oriented along the x axis, what is the electric field at x = 15 cm?

A charged particle is placed in an electric field that varies with location.No force is exerted on this charge:

Two point charges are arranged as shown.In which region could a third charge +1 C be placed so that the net electrostatic force on it is zero?

A spherical shell has an inner radius of 3.7 cm and an outer radius of 4.5 cm.If charge is distributed uniformly throughout the shell with a volume density of 6.1*10^-4 C/m³ the total charge is:

An electric dipole consists of a particle with a charge of +6 * 10^-6 C at the origin and a particle with a charge of -6* 10^-6 C on the x axis at x = 3 * 10^-3 m.The direction of the electric field due to the dipole at points on the x axis is:

Two point particles, one with charge +8 10^-9 C and the other with charge-2 10^-9 C, are separated by 4 m.The electric field midway between them is:

Two charged point particles are located at two vertices of an equilateral triangle and the electric field is zero at the third vertex.We conclude:

A disk with a uniform positive surface charge density lies in the x-y plane, centered on the origin.The disk contains 2.5 x 10^-6 C/m² of charge, and is 7.5 cm in radius.What is the electric field at z = 15 cm?

Two point particles, with the same charge, are located at two vertices of an equilateral triangle.A third charged particle is placed so the electric field at the third vertex is zero.The third particle must:

The magnitude of the force of a 400-N/C electric field on a 0.02-C point charge is:

An electric dipole consists of a particle with a charge of +6 * 10^-6 C at the origin and a particle with a charge of -610^-6 C on the x axis at x = 3 10^-3 m.Its dipole moment is:

A disk with a uniform positive surface charge density lies in the x-y plane, centered on the origin.Along the positive z axis, the direction of the electric field is:

Quiz 22: Electric Fields

The electric field due to a uniform distribution of charge on a spherical shell is zero:

A 200-N/C electric field is in the positive x direction.The force on an electron in this field is:

Charge is placed on the surface of a 2.7-cm radius isolated conducting sphere.The surface charge density is uniform and has the value 6.9 * 10-6 C/m2.The total charge on the sphere is:

A total charge of 6.3 *10-8 C is distributed uniformly throughout a 2.7-cm radius sphere.The volume charge density is:

Comparing the field of a single point charge with the field of an electric dipole,

A cylinder has a radius of 2.1 cm and a length of 8.8 cm.Total charge 6.1 * 10-7 C is distributed uniformly throughout.The volume charge density is:

An electron traveling north enters a region where the electric field is uniform and points north.The electron:

An electric dipole consists of two charges, ±2.5 µC, separated by 1.0 x 10-4 m and centered on the origin.If the dipole is oriented along the x axis, what is the electric field at x = 15 cm?