Question 1

A square has equal positive charges at three of its corners, as shown. The direction of the electric field at point P is

Accepted Answer

The answer of  A square has equal positive charges...

Question 2

The point P is on the axis of a ring of charge, and all vectors shown lie in the yz plane. The negatively charged ring lies in the xz plane. The vector that correctly represents the direction of the electric field at this point is

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The answer of  The point P is on the...

Question 3

Use the picture for the next problem. A negatively charged particle moving with speed v enters a region of uniform electric field E. -If the charge q = 1 nC, mass m = 1 * 10^-14 kg, speed v = 10⁵ m/s, the electric field strength E = 2 *10⁵ V/m, and width, w, of the electric field is 0.2 m, what is the speed of the particle when it emerges from the other side?

Accepted Answer

We can use the equation of motion for a charged particle in an electric field:

F = ma = qE

where F is the force on the particle, m is its mass, a is its acceleration, q is its charge, and E is the electric field strength.

Since the direction of the force is opposite to the direction of the electric field, the particle will slow down as it moves through the field. The acceleration can be found by rearranging the equation above:

a = qE/m

The time taken for the particle to cross the field is given by:

t = w/v

where w is the width of the field and v is the initial speed of the particle.

Using the equations of motion, we can find the final speed of the particle as it emerges from the other side of the field:

v' = sqrt(v^2 - 2ad)

where d is the distance traveled by the particle in the field, which is equal to w.

Substituting the given values, we get:

a = (1 nC)(2*10^15 V/m)/(1.6*10^-19 kg) = 0.0125 m/s^2
t = 0.2 m / (10^15 m/s) = 2*10^-16 s
d = w = 0.2 m

Using these values, we get:

v' = sqrt((10^15 m/s)^2 - 2(0.0125 m/s^2)(0.2 m)) = 1.08*10^15 m/s

Therefore, the answer is C.

Question 4

An electron is released from rest in a uniform electric field. If the electric field is 1.25 kN/C, at the end of 20 ns the electron's velocity will be approximately

Accepted Answer

The answer of An electron is released from rest in...

Question 5

Which of the following statements about electric field lines is not true?

Accepted Answer

Electric field lines do not cross midway between charges that have equal magnitude and sign. They instead diverge outward. This violates the principle that the direction of the electric field is always tangential to the electric field lines.

Question 6

An oil droplet of mass 1.00 *10^-14 kg loses an electron while it is in an electric field of 1.00 *10⁶ N/C. The resulting change in the acceleration of the oil droplet is approximately

Accepted Answer

The answer of An oil droplet of mass 1.00 *10^-14...

Question 7

An electron is released from rest in a uniform electric field. If the electric field is 3.65 kN/C, at the end of 15 ns the electron's velocity will be approximately

Accepted Answer

We can use the equation for the acceleration of an electron in a uniform electric field:

a = F/m = eE/m

where a is the acceleration, F is the force, m is the mass of the electron, e is the charge of the electron, and E is the electric field strength.

Since the electron is initially at rest, its initial velocity is zero, and we can use the kinematic equation:

v = at

where v is the final velocity, a is the acceleration, and t is the time.

Plugging in the given values, we have:

a = eE/m = (1.6 x 10^-19 C)(3.65 x 10^3 N/C)/(9.11 x 10^-31 kg) = 6.4 x 10^14 m/s^2

t = 15 x 10^-9 s

v = at = (6.4 x 10^14 m/s^2)(15 x 10^-9 s) = 9.6 x 10^6 m/s = 9.6 x 10^3 km/s

However, the answer choices are given in scientific notation, so we need to convert our answer to that format:

v = 9.6 x 10^3 m/s = 9.6 x 10^3 / 10^3 km/s = 9.6 x 10^0 km/s = 9.6 km/s

Therefore, the closest answer choice is A, 9.6 x 10^6 m/s in scientific notation.

Question 8

A small positive charge is located at A. The vector that gives the direction of the electric field at point P is

Accepted Answer

The electric field points away from a positive charge, so the vector should point upwards and to the right. Choice B is the only option that matches this direction.

Question 9

A square has equal positive charges at three of its corners, as shown. The direction of the electric field at point P is

Accepted Answer

The answer of  A square has equal positive charges...

Question 10

Two electric dipoles, p₁ and p₂, are arranged as shown. The first dipole is not free to rotate but the second dipole can rotate in any direction. Which way will p₂ rotate? The directions represent the following: 1 - clockwise, 2 - counter-clockwise, 3 - rotate about axis of the dipole rolling up, and 4 - rotate about axis of the dipole rolling down.

Accepted Answer

The arrangement of the dipoles creates a torque on the second dipole, which would cause it to rotate counter-clockwise in order to align with the field direction of the first dipole.

Question 11

The figure shows the field lines for two charges. What is the ratio of the top charge to the bottom charge?

Accepted Answer

The answer of  The figure shows the field lines...

Question 12

In a uniform electric field a proton has

Accepted Answer

In a uniform electric field, a charged particle like a proton experiences a constant force in the direction of the field. This constant force results in an approximately constant acceleration in the direction of the electric field, according to Newton's second law of motion (F = ma).

Question 13

In the figure, the direction of the electric field at a point equidistant from two equally charged bodies A and B is indicated by a vector. The direction of the vector indicates that

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The answer of  In the figure, the direction of...

Question 14

Use the picture for the next problem.  A negatively charged particle moving with speed v enters a region of uniform electric field E.
-Using the direction compass on the right, the direction of the force on the charge is

Accepted Answer

The direction of the force on a negatively charged particle moving in a uniform electric field is opposite to the direction of the electric field. In this case, the electric field is pointing to the right, so the force on the negatively charged particle will be to the left, which corresponds to direction 3 on the direction compass.

Question 15

A square has equal positive charges at three of its corners and a negative charge at the third. The direction of the electric field at point P is

Accepted Answer

Based on the given information, we can draw a diagram of the charges at the corners of the square and use the principle of superposition to determine the direction of the electric field at point P. By adding up the electric field contributions from each individual charge, we find that the net electric field points in the direction shown in choice B.

To see this, consider the electric field from the positive charge q at the upper left corner of the square. This field points to the right and downward, since the positive charge repels positive test charges and attracts negative ones. Similarly, the electric field from the positive charge q at the upper right corner points downward and to the left, while the electric field from the positive charge q at the lower left corner points upward and to the right.

Finally, the electric field from the negative charge -q at the lower right corner points to the left and upward, since negative charges attract positive test charges and repel negative ones. When we add up these four electric field vectors, we find that they combine to produce a net electric field pointing in the direction shown in choice B.

Question 16

Which of the following statements about electric field lines are true?

Accepted Answer

All of these statements are true. 
A) Electric field lines are symmetrical around an isolated charge because the electric field is a conservative field, meaning the work done by the field is independent of the path taken by the charge. 
B) At a distance from a system of charges, the field lines will be radial and equally spaced, as if they came from a single point charge, which is the net charge of the entire system. 
C) Electric field lines always begin on a positive charge, or at infinity where there is no charge, and end on a negative charge or at infinity, again, where there is no charge. 
D) The number of lines leaving a positive charge or entering a negative charge is proportional to the charge. This is because the density of electric field lines is proportional to the magnitude of the electric field, which in turn is proportional to the charge.

Question 17

If nonelectric forces are negligible, a positively charged particle released from rest in a nonuniform electric field

Accepted Answer

Since the particle is positively charged, it will experience a force in the direction of the electric field. Therefore, the particle will accelerate in the direction of the field.

Question 18

In the diagram, Q₁ = 6.0 $\mu$C and Q₂ = -6.0 $\mu$C. If Q₂ has a mass of 2.0 g, a uniform electric field of 1.5 kN/C imposed in the positive y direction would give this particle an acceleration in the y direction of approximately

Accepted Answer

The answer of In the diagram, Q₁ = 6.0...

Question 19

In the diagram, Q₁ = 9.0 $\mu$C and Q₂ = -9.0 $\mu$C. If Q₂ has a mass of 3.0 g, a uniform electric field of 1.8 kN/C imposed in the positive y direction would give this particle an acceleration in the y direction of approximately

Accepted Answer

The answer of In the diagram, Q₁ = 9.0...

Question 20

An electric dipole consists of a positive charge separated from a negative charge of the same magnitude by a small distance. Which, if any, of the diagrams best represents the electric field lines around an electric dipole?

Accepted Answer

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

Quiz 1: The Electric Field I: Discrete Charge Distributions

A square has equal positive charges at three of its corners, as shown. The direction of the electric field at point P is

The point P is on the axis of a ring of charge, and all vectors shown lie in the yz plane. The negatively charged ring lies in the xz plane. The vector that correctly represents the direction of the electric field at this point is

An electron is released from rest in a uniform electric field. If the electric field is 1.25 kN/C, at the end of 20 ns the electron's velocity will be approximately

Which of the following statements about electric field lines is not true?

An oil droplet of mass 1.00 10^-14 kg loses an electron while it is in an electric field of 1.00 10⁶ N/C. The resulting change in the acceleration of the oil droplet is approximately

An electron is released from rest in a uniform electric field. If the electric field is 3.65 kN/C, at the end of 15 ns the electron's velocity will be approximately

A small positive charge is located at A. The vector that gives the direction of the electric field at point P is

A square has equal positive charges at three of its corners, as shown. The direction of the electric field at point P is

The figure shows the field lines for two charges. What is the ratio of the top charge to the bottom charge?

In a uniform electric field a proton has

In the figure, the direction of the electric field at a point equidistant from two equally charged bodies A and B is indicated by a vector. The direction of the vector indicates that

Use the picture for the next problem. A negatively charged particle moving with speed v enters a region of uniform electric field E. -Using the direction compass on the right, the direction of the force on the charge is

A square has equal positive charges at three of its corners and a negative charge at the third. The direction of the electric field at point P is

Which of the following statements about electric field lines are true?

If nonelectric forces are negligible, a positively charged particle released from rest in a nonuniform electric field

An electric dipole consists of a positive charge separated from a negative charge of the same magnitude by a small distance. Which, if any, of the diagrams best represents the electric field lines around an electric dipole?

Quiz 1: The Electric Field I: Discrete Charge Distributions

A square has equal positive charges at three of its corners, as shown. The direction of the electric field at point P is

The point P is on the axis of a ring of charge, and all vectors shown lie in the yz plane. The negatively charged ring lies in the xz plane. The vector that correctly represents the direction of the electric field at this point is

An electron is released from rest in a uniform electric field. If the electric field is 1.25 kN/C, at the end of 20 ns the electron's velocity will be approximately

Which of the following statements about electric field lines is not true?

An oil droplet of mass 1.00 *10-14 kg loses an electron while it is in an electric field of 1.00 *106 N/C. The resulting change in the acceleration of the oil droplet is approximately

An electron is released from rest in a uniform electric field. If the electric field is 3.65 kN/C, at the end of 15 ns the electron's velocity will be approximately

A small positive charge is located at A. The vector that gives the direction of the electric field at point P is

A square has equal positive charges at three of its corners, as shown. The direction of the electric field at point P is

The figure shows the field lines for two charges. What is the ratio of the top charge to the bottom charge?

In a uniform electric field a proton has

In the figure, the direction of the electric field at a point equidistant from two equally charged bodies A and B is indicated by a vector. The direction of the vector indicates that

Use the picture for the next problem. A negatively charged particle moving with speed v enters a region of uniform electric field E. -Using the direction compass on the right, the direction of the force on the charge is

A square has equal positive charges at three of its corners and a negative charge at the third. The direction of the electric field at point P is

Which of the following statements about electric field lines are true?

If nonelectric forces are negligible, a positively charged particle released from rest in a nonuniform electric field

In the diagram, Q1 = 6.0 μ\muμ C and Q2 = -6.0 μ\muμ C. If Q2 has a mass of 2.0 g, a uniform electric field of 1.5 kN/C imposed in the positive y direction would give this particle an acceleration in the y direction of approximately

In the diagram, Q1 = 9.0 μ\muμ C and Q2 = -9.0 μ\muμ C. If Q2 has a mass of 3.0 g, a uniform electric field of 1.8 kN/C imposed in the positive y direction would give this particle an acceleration in the y direction of approximately

An electric dipole consists of a positive charge separated from a negative charge of the same magnitude by a small distance. Which, if any, of the diagrams best represents the electric field lines around an electric dipole?

An oil droplet of mass 1.00 10^-14 kg loses an electron while it is in an electric field of 1.00 10⁶ N/C. The resulting change in the acceleration of the oil droplet is approximately