Deck 22: Electric Fields and Gausss Law

Question 1

A point charge is placed on the x-axis at the origin.The electric field produce at x = 40.0 cm is 157 N/C? What is the point charge?

A)4.20 * 10^-9 C
B)4.00 * 10^-9 C
C)2.80 * 10^-9 C
D)1.20 * 10^-9 C
E)3.40 * 10^-9 C

Answer 1

2.80 * 10^-9 C

Question 2

A + 5.00-nC point charge is placed on the x axis at x = 1.00 m,and a - 6.00-nC point charge is placed on the y axis at y = -2.00 m.What is the direction of the electric field at the origin?

A)189 ^$\circ$
B)191 ^$\circ$
C)193 ^$\circ$
D)195 ^$\circ$
E)197 ^$\circ$

Answer 2

197 ^$\circ$

Question 3

Two ions are placed on the x-axis.One has a charge of + e and is located at the origin.The other has a charge of -4e and is located at x = + d,where d > 0.Where on the x-axis is the net electric field equal to zero?

A)x = -2d
B)x = -d
C)x = + d
D)x = + 2d

Answer 3

x = -d

Question 4

An electric dipole has opposite charges of 2.0 * 10^-15 C which are separated by a distance of 0.40 mm.It is oriented at 40 ^$\circ$ with respect to a uniform electric field of 1.0 * 10³ N/C.Determine the magnitude of the torque exerted on the dipole by the electric field.

A)2.2 * 10^-16 Nm
B)3.8 * 10^-16 Nm
C)5.1 * 10^-16 Nm
D)6.7 * 10^-16 Nm
E)8.0 * 10^-16 Nm

Question 5

At a distance d from a charge,the magnitude of the electric field is

A)E/4
B)E/2
C)2E
D)4E
E)What would be the magnitude of the electric field a distance d/2 from the same charge?

Question 6

Two point charges are placed on two of the corners of a triangle as shown.Find the magnitude of the electric field at the third corner of the triangle.

A)3.9 * 10⁶ N/C
B)4.5 * 10⁶ N/C
C)5.4 * 10⁶ N/C
D)6.7 * 10⁶ N/C
E)7.1 * 10⁶ N/C

Question 7

A point charge q = 4.00 * 10^-9 C is placed on the x-axis at the origin.What is the electric field produce at x = 40.0 cm?

A)90.0 N/C
B)108 N/C
C)157 N/C
D)201 N/C
E)225 N/C

Question 8

A point charge of 7.8 $\mu$ C is located inside a hemisphere,which consists of two surfaces: a flat disk topped by half a sphere.If the electric flux through the half-sphere is 5.3 * 10⁵ Nm²/C,what is the flux through the flat disk section?

A)2.3 * 10⁵ Nm²/C
B)3.5 * 10⁵ Nm²/C
C)5.3 * 10⁵ Nm²/C
D)8.83 * 10⁵ Nm²/C
E)More information is required to determine this flux.

Question 9

A + 3.5-nC point charge is placed at one corner of a square (2.0 m on a side),and a -5.7-nC charge is placed on a corner diagonally away from the first charge.What is the magnitude of the electric field at either of the two unoccupied corners?

A)26 N/C
B)23 N/C
C)18 N/C
D)15 N/C
E)7.6 N/C

Question 10

Two electrons are located at two of the vertices of an equilateral triangle,one at each vertex.The length of one side of the triangle is 1.00 nm.What is the magnitude of the net electric field at the third vertex?

A)1.44 * 10⁹ N/C
B)2.03 * 10⁹ N/C
C)2.49 * 10⁹ N/C
D)2.88 * 10⁹ N/C

Question 11

Electric field lines always point from

A)positive charges to positive charges.
B)negative charges to negative charges.
C)positive charges to negative charges.
D)negative charges to positive charges.

Question 12

Two infinite non-conducting plates are parallel to each other,with an interplate distance of d = 10.0 cm.Each plate carries a uniform two-dimensional charge density of 7.4 $\mu$ C/m².What is the magnitude of the electric field at a point located a quarter of the way between the plates?

A)0 N/C
B)3.14 * 10⁵ N/C
C)4.18 * 10⁵ N/C
D)8.36 * 10⁵ N/C
E)1.674 * 10⁶ N/C

Question 13

A point charge of 7.8 $\mu$ C is located inside a hemisphere,which consists of two surfaces: a flat disk topped by half a sphere.If the electric flux through the flat disk is 3.5* 10⁵ Nm²/C,what is the flux through the half-sphere section?

A)2.3 * 10⁵ Nm²/C
B)3.5 * 10⁵ Nm²/C
C)5.3 * 10⁵ Nm²/C
D)8.83 * 10⁵ Nm²/C
E)More information is required to determine this flux.

Question 14

Two infinite,uniformly charged,flat surfaces are mutually perpendicular.One of the sheets has a charge density of + 20.0 pC/m²,and the other carries a charge density of -50.0 pC/m².What is the magnitude of the electric field at any point not on either surface?

A)2.75 N/C
B)2.82 N/C
C)3.04 N/C
D)3.37 N/C
E)4.45 N/C

Question 15

A solid sphere of diameter 20 cm has a non-uniform charge density where A = 0.600 * 10^-14 C/m⁵.Determine the total charge,Q,within the volume of the sphere.

A)1.5 * 10^-19 C
B)2.4 * 10^-19 C
C)3.6 * 10^-19 C
D)4.0 * 10^-19 C

Question 16

In the opposite corners of a square there are two identical ions.Each has a charge of -e.The length of one side of he square is L.What is the magnitude of the net electric field caused by the two negative ions at both of the empty corners of the square?

A)ke/2L²
B)ke/L²
C) ke/L²
D)2ke/L²

Question 17

A point charge + Q is located on the x-axis at x = a,and a second point charge -Q is located on the x axis at x = -a.A cubic Gaussian surface with sides l = 3a is centered at the origin.The flux through this Gaussian surface is

A)zero.
B)greater than zero.
C)less than zero.
D)None are correct.

Question 18

An electric dipole has opposite charges of 5.0 * 10^-15 C which are separated by a distance of 0.50 mm.It is oriented in a uniform electric field of 1.0 * 10³ N/C.If the magnitude of the torque exerted on the dipole by the electric field is 1.05 * 10^-15 Nm,what is its orientation with respect to the electric field?

A)10 ^$\circ$
B)25 ^$\circ$
C)33 ^$\circ$
D)41 ^$\circ$
E)55 ^$\circ$

Question 19

A 4.00 * 10^-9 C point charge is placed at the origin.Where on the x-axis is the electric field produced by the point charge 157 N/C?

A)32 cm
B)22 cm
C)40 cm
D)48 cm
E)28 cm

Question 20

Two identical point charges Q are placed each diagonally opposite corners of a square (1.0 m on a side).The magnitude of the electric field at either of the two unoccupied corners is 19.1 N/C.The absolute value of the charge Q is

A)1.5 nC.
B)2.4 nC.
C)3.2 nC.
D)4.7 nC.
E)5.9 nC.

Question 21

A + 5.0 C charge is located at the origin.A -13.0 C charge is placed at x = 1.0 m.At what finite location(s)on the x axis will the electric field be equal to zero?

A)in between the particles,closer to the positive particle
B)in between the particles,closer to the negative particle
C)not in between,but closer to the positive particle
D)not in between,but closer to the negative particle
E)It can never be zero.

Question 22

A 3.5-C point charge sits in the center of a 1 m cube.What is the electric flux through one side of the cube?

A)5.0 * 10¹⁰ Nm²/C
B)3.3 * 10¹⁰ Nm²/C
C)4.5 * 10¹⁰ Nm²/C
D)6.6 * 10¹⁰ Nm²/C
E)7.2 * 10¹⁰ Nm²/C

Question 23

The figure shows a hollow conducting spherical shell with an inner radius of 8 cm and an outer radius of 10 cm.A charge,q,placed at the center of the shell causes an electric field at the inner surface of the shell,E_i,which has a magnitude of 80 N/C and points toward the center of the sphere.Additionally,there is an electric field at the outer surface,E_o,which has a magnitude of 80 N/C and points away from the center of the sphere.Determine the charge on the spherical shell.

A)0 C
B)+ 5.69 * 10^-11 C
C)+ 8.89 * 10^-11 C
D)+ 1.46 * 10^-10 C

Question 24

A 22-g metal ball hangs from a string.An electric field of 15,000 N/C,pointing to the right,is then turned on.After the electric field is turned on,the ball hangs at a 25 degree angle away from the vertical.What is the charge on the ball?

A)6.8 * 10^-7 C
B)6.7 * 10^-6 C
C)6.1 * 10^-6 C
D)1.4 * 10^-5 C
E)3.1 *10^-5 C

Question 25

In which of the following situations is the magnitude of the electric field the strongest.

A)a point 1 m from a 1-C point charge
B)a point 1 m along a perpendicular line from the center of a 1-m rod with a charge of 1-C
C)a point 1 m along a perpendicular line from the center of a 1-m diameter disk of charge 1 C
D)a point 1 m from the end of a 1m rod with a charge of 1 C along a line running longitudinal with the rod
E)All of the choices have the same electric field.

Question 26

A 3.5-C point charge sits in the center of a cube and the electric flux through one of the cube's sides is 6.6 * 10¹⁰ Nm²/C .What is the length of one of the edges of the cube?

A)0.50 m
B)1.0 m
C)1.5 m
D)0.67 m
E)the size of the cube cannot be uniquely determined from the given information

Question 27

In which of the following situations is the electric field the strongest?

A)a point 1 m from a 1-C point charge
B)a point 1 m (perpendicular distance)from the center of a 1 m wire with 1-C of charge distributed on it
C)a point 1 m (perpendicular distance)from the center of a 1 m² sheet of charge with 1 C arranged on it
D)a point 1 m from the surface of a spherical shell of charge with a radius of 1 m
E)a point 1 m from the surface of a spherical shell of charge with a radius of 0.5 m

Question 28

A point charge sits in the center of a 1 m cube.The electric flux through one side of the cube is 7.2 * 10¹⁰ Nm²/C.What is the charge at the center of the cube?

A)3.5 C
B)4.6 C
C)8.9 C
D)6.0 C
E)3.8 C

Question 29

A charged metal ball of mass,m hangs from a string.An electric field of 15,000 N/C,pointing to the right,is then turned on.After the electric field is turned on,the ball hangs at a 20 degree angle away from the vertical.If the charge on the ball is 6.1 * 10^-6 C,what is the tension in the string?

A)0.238 N
B)0.279 N
C)0.303 N
D)0.268 N
E)0.291 N

Question 30

A cubical box has six faces,each 20 cm * 20 cm.The flux through each face is (the sides are labeled like a die,sides 1 and 6 are opposite to each other,as are 2 and 5,and 3 and 4. Side Flux (Nm²/C)
1 -120
2 + 300
3 -100
4 + 600
5 -40
6 -150
Find the net charge inside the cube.

A)1.7 * 10^-10 C
B)4.8 * 10^-10 C
C)2.2 * 10^-9 C
D)4.3 * 10^-9 C
E)More information is needed.

Question 31

Which of the following surfaces have the largest total electric flux?

A)a sphere of radius 1 m with a 1-C charge placed inside at the center
B)a sphere of radius 1 m with a 1-C charge placed inside but off-center
C)a cylinder of radius 1 m and length 1 m with a 1-C charge placed inside
D)a 1-m cube with a 1-C charge placed in the center
E)a sphere of radius 1 m with a 2-C charge placed inside and a 1-C charge placed outside

Question 32

Inside a spherical surface is a 5.3 * 10^-6C and a -2.2 * 10^-6 C charge.What is the total electric flux through the surface of the sphere in units of N m²/C?

A)3.4 * 10^-16
B)2.8 * 10⁴
C)3.5 * 10⁵
D)3.1 * 10⁶
E)To find the flux,the area must be known.

Question 33

A metal ball hangs from a string.An electric field of 15,000 N/C,pointing to the right,is then turned on.After the electric field is turned on,the ball hangs at a 25 degree angle away from the vertical.If the charge on the ball is 1.4 * 10^-5 C,what is the mass of the ball?

A)49 g
B)22 g
C)52 g
D)46 g
E)37 g

Question 34

The electric flux through a spherical Gaussian surface of radius R centered about an amount of charge Q is 1200 N/C m².What is the electric flux through a cubic Gaussian surface of side R centered about the same charge Q?

A)less than 1200 Nm²/C
B)more than 1200 Nm²/C
C)equal to 1200 Nm²/C
D)It cannot be determined with given parameters.

Question 35

What is the electric field 0.25 m away from a -6.5 $\mu$ C point charge?

A)6.1 N/C towards the point charge
B)6.1 N/C away from the point charge
C)9.4 * 10⁵ N/C towards the point charge
D)9.4 * 10⁵ N/C away from the point charge
E)1.5 N/C towards the point charge

Question 36

A 63 g metal ball hangs from a string.An electric field,pointing to the right,is then turned on.After the electric field is turned on,the ball hangs at a 25 degree angle away from the vertical.If the charge on the ball is 1.4 *10^-5 C,what is the magnitude of the electric field?

A)12000 N/C
B)15000 N/C
C)21000 N/C
D)18000 N/C
E)25000 N/C

Question 37

A point charge of -1.4 $\mu$ C is located at the center of a right cylinder.If the electric flux through one of the circular end caps is -2.4 * 10⁴ Nm²/C,what is the flux through the cylindrical section between the end caps?

A)1.1 * 10⁵ Nm²/C
B)-1.1 * 10⁵ Nm²/C
C)1.3 * 10⁵ Nm²/C
D)-1.3* 10⁵ Nm²/C
E)More information is required to determine this flux.

Question 38

Occasionally parts of the lunar surface develop an electric field 20 kN/C,allowing dust particles that have been charged by cosmic rays to become levitated.How many electrons must be placed on a 1.0-g dust particle if it is to be levitated in this field? The acceleration due to gravity on the surface of the moon is 1.62 m/s².

A)3.2 * 10⁷
B)5.1 * 10¹¹
C)3.2 * 10¹⁴
D)8.9 * 10²²
E)2.0 * 10³⁸

Question 39

The figure shows a hollow conducting spherical shell with an inner radius of 8 cm and an outer radius of 10 cm.A charge,q,placed at the center of the shell causes an electric field at the inner surface of the shell,E_i,which has a magnitude of 80 N/C and points toward the center of the sphere.Additionally,there is an electric field at the outer surface,E_o,which has a magnitude of 80 N/C and points away from the center of the sphere.Determine the charge on the inner surface of the spherical shell.

A)0 C
B)+ 5.69 * 10^-11 C
C)+ 8.89 * 10^-11 C
D)+ 1.46 * 10^-10 C

Question 40

Three charges are placed at the corners of an equilateral triangle that is 0.16 m on each side.The first charge is 3.4 $\mu$ C,the second is 2.2 $\mu$ C and the third is 1.6 $\mu$ C.What is the magnitude of the electric field at the center of the triangle due to the three charges?

A)2.9 * 10⁵ N/C
B)5.9 * 10⁴ N/C
C)2.3 * 10⁵ N/C
D)1.7 * 10⁶ N/C
E)1.5 * 10⁵ N/C

Question 41

Four electric fields,E₁,E₂,E_3, and E₄ are produced at four different points,1,2,3,and 4 by charges q,2q,q,and 2q,respectively.If the distances of the four points from the charges are 10,10,20,and 20 cm,respectively,rank in order from smallest to largest their electric field strengths.

A)E₃ < E₄ < E₂ < E₁
B)E₃ < E₁ < E₂ < E₄
C)E₂ < E₁ < E₄ < E₃
D)E₃ < E₄ < E₁ < E₂

Question 42

A solid,insulating sphere of radius a = 2 cm has a total charge Q = 10 nC which is uniformly distributed.Using Gauss's Law determine the magnitude of the electric field at a point inside sphere which is 1 cm from its center.

A)1.13 * 10⁵ N/C
B)2.25 * 10⁵ N/C
C)0 N/C
D)3.61 * 10⁵ N/C

Question 43

A thin glass rod is bent into a semicircle of radius R.A charge + Q is uniformly distributed along the upper half,and a charge -Q is uniformly distributed along the lower half,as shown in the figure.If R = 10 cm and the electric field E at point P is 4.81 * 10⁴ N/C in -y direction,what is the charge,Q? Point P is at the center of the semicircle.

A)62 nC
B)10 nC
C)42 nC
D)27 nC
E)51 nC

Question 44

Three + 4.0-mC fixed point charges are located at (0.0 mm,0.0 mm),(2.0 mm,2.0 mm),and (2.0 mm,-2.0 mm).What is the magnitude of the electric field at the position (2.0 mm,0.0 mm)?

A)0.0 N/C
B)1.8 * 10¹⁰ N/C
C)2.7 * 10¹⁰ N/C
D)9.0 * 10¹² N/C
E)2.7 * 10¹³ N/C

Question 45

The electrons in a particle beam enter an electric field of 2000 N/C and are stopped in a distance of 1 m.What was the kinetic energy of one of these electrons prior to entering the electric field?

A)1.2 * 10^-16 J
B)3.7 * 10^-16 J
C)1.6 * 10^-16 J
D)2.5 * 10^-16 J
E)3.2 * 10^-16 J

Question 46

A thin glass rod is bent into a semicircle of radius R.A charge + Q is uniformly distributed along the upper half,and a charge -Q is uniformly distributed along the lower half,as shown in the figure.If Q = 10 nC and the electric field E at point P is 5.85 * 10⁴ N/C in -y direction,what is the radius of the semicircle,R? Point P is at the center of the semicircle.

A)10 cm
B)9.0 cm
C)14 cm
D)16 cm
E)12 cm

Question 47

Consider the Earth to have a uniformly charged surface with density $\sigma$ per unit area.What is the value of $\sigma$ if objects near the surface,carrying charge Q and having mass m,experience no net force?

A)+ $\varepsilon$ ₀._omg/Q
B)- $\varepsilon$ ₀._omg/Q
C)+ 2 $\varepsilon$ ₀._omg/Q
D)-2 $\varepsilon$ ₀._omg/Q
E)Either A or B is correct,depending on the sign of Q.

Question 48

A thin glass rod is bent into a semicircle of radius R.A charge + Q is uniformly distributed along the upper half,and a charge -Q is uniformly distributed along the lower half,as shown in the figure.If Q = 10 nC and R = 10 cm,find the magnitude and direction of the electric field E (in component form)at point P,the center of the semicircle.

A)3.61 * 10⁴ N/C in + y direction
B)3.61 * 10⁴ N/C in -y direction
C)1.15 * 10⁴ N/C in + x direction
D)1.15 * 10⁴ N/C in -y direction

Question 49

An electric dipole is placed into a uniform electric field directed to the right as shown in the figure.What motion will the dipole have in this electric field?

A)It will move to the right.
B)It will move to the left.
C)It will rotate clockwise.
D)It will rotate counter-clockwise
E)It will move to the right and rotate clockwise.

Question 50

The electrons in a particle beam each have a kinetic energy of 1.6 * 10^-16 J.The magnitude of the electric field that would stop the electrons in a distance of 1 m is

A)2000 N/C.
B)1000 N/C.
C)780 N/C.
D)620 N/C.
E)545 N/C.

Question 51

A point charge q is located at the center of a sphere of radius R.Also concentrically inside the sphere is a uniform ring having linear charge density $\lambda$ and radius a (a <R).The flux through the sphere is

A)q/ $\varepsilon$ ₀.
B)(q + $\lambda$ *2 $\pi$ a)/ $\varepsilon$ ₀.
C)(q - $\lambda$ *2 $\pi$ a)/ $\varepsilon$ ₀.
D)0.

Question 52

A point charge q is located at the center of a sphere of radius R.The sphere is then surrounded concentrically by a uniform ring having linear charge density $\lambda$ and radius a (a >R).The flux through the sphere is

A)q/ $\lambda$ _o.
B)(q + $\lambda$ *2 $\pi$ a)/ $\varepsilon$ ₀.
C)(q - $\lambda$ *2 $\pi$ a)/ $\varepsilon$ ₀.
D)0.

Question 53

A spherical Gaussian surface of radius R surrounds a point charge Q.If the radius of the sphere is doubled,the electric flux through its surface is

A)doubled.
B)reduced by ½.
C)increased by 4.
D)reduced by 4.
E)the same.

Question 54

The electric field is zero at some point on a line that runs between the centers of two charged spheres.What can one say about this situation?

A)The charges on the two spheres are opposite in sign.
B)The charges on the two spheres have the same sign.
C)The point of interest is equidistant from the two spheres' centers.
D)There is no such point on the line.
E)None are correct.

Question 55

A cannon shoots 5.0-kg cannon ball that carries a charge of 3.0 Coulombs at some angle above horizontal ground in a region in which there is a uniform electric field E and gravitational acceleration is straight down,-9.8 m/s² ŷ.If the ball travels half the horizontal distance before striking the ground that it would have if there were no electric field,what is the magnitude of the electric field?

A)+ 16 N/C ŷ
B)-16N/C ŷ
C)+ 49 N/C ŷ
D)-49 N/C ŷ
E)Cannot answer-the angle of launch is needed.

Question 56

The electrons in a particle beam each have a kinetic energy of 1.6 * 10^-16 J,enter an electric field of 2000 N/C and are stopped.What is the stopping distance of these electrons?

A)3.2 m
B)2.0 m
C)0.25 m
D)4.0 m
E)0.50 m

Question 57

A cannon shoots a charged,5.0-kg cannon ball at some angle above horizontal ground in a region in which the electric field is given by 12.0 N/C ŷ,while gravitational acceleration is straight down,-9.8 m/s² ŷ.If the ball travels half the distance it would have if there were no electric field,what is the charge on the cannon ball?

A)+ 4.1C
B)-4.1C
C)+ 12C
D)-12C
E)Cannot answer-the angle of launch is needed.

Question 58

A small metal ball with a mass of 10 grams and a charge of 5.0 mC is located in a region of space with an electric field of 12 N/C directed to the east.The ball is released from rest at a distance of 30 cm above the ground.What is the speed of the ball just before it hits the ground?

A)1.0 m/s
B)1.5 m/s
C)2.0 m/s
D)2.8 m/s
E)3.9 m/s

Question 59

Four electric fields,E₁,E₂,E_3, and E₄ are produced at four different points,1,2,3,and 4 by charges q,2q,q,and 2q,respectively.If the distances of the four points from the charges are 10,10,20,and 20 cm,respectively,rank in order from largest to smallest their electric field strengths.

A)E₁ > E₂ > E₃ > E₄
B)E₂ > E₁ > E₃ > E₄
C)E₂ > E₁ > E₄ > E₃
D)E₄ > E₂ > E₃ > E₁

Question 60

An insulating solid sphere of radius a has a uniform volume charge density $\rho$ and total positive charge q.The strength of the electric field inside the sphere at a distance r from the center (r < a)is proportional to

A)a.
B)r.
C)1/r².
D)1/r³.
E)1/a².

Question 61

The electric field at point A is as shown.What must be the relation between charges q₁ and q₂?

A)q₁ = q₂
B)q₁ = -q₂
C)q₁ = (2)^1/2q₂
D)q₁ = -(2)^1/2q₂
E)It is not possible.

Question 62

What is the mass of an object with a net charge of + 10 mC whose weight is balanced by an electric field,E = 300 N/C,as shown?

A)457 g
B)1305 g
C)306 g
D)15.35 g
E)2.41 g

Question 63

A charge q₁ = 1.0 $\mu$ C is placed at the origin of an x-axis and another charge q₂ = 2.0 $\mu$ C is placed at position x = 10 cm.Find a point on the axis where the electric field due to these two charges is zero.

A)x = 2.6 cm
B)x = -3.2 cm
C)x = 4.2 cm
D)x = -10.0 cm
E)x = 5 cm

Question 64

A small charge of -11 $\mu$ C is in a constant vertical electric field.If the charge has a mass of 0.022 kg and its acceleration is -1.0 m/s²(in the negative y-direction),what is the value of the constant electric field? There is no gravity.

A)+1.32 * 10³ N/C
B)-1.32 * 10³ N/C
C)+2.00 * 10³ N/C
D)-2.00 * 10³ N/C
E)+2.42 * 10³ N/C

Question 65

Consider a proton placed near an infinite plane of positive charge with no other objects close by.The proton would

A)accelerate away from the plane of charge with ever decreasing acceleration.
B)remain motionless.
C)accelerate toward the plane of charge with ever increasing acceleration.
D)move toward the plane of charge at constant acceleration.
E)move away from the plane of charge at constant acceleration.

Question 66

A metal sphere of radius R = 30 cm carries a total charge Q = 2.0 $\mu$ C.What is the magnitude of the electric field at a point 5 m away? The point is located on the positive x-axis,where the center of the sphere is located at the origin.

A)7.19 * 10² N/C
B)2.16 * 10^-16 N/C
C)1.59 * 10^-3 N/C
D)9.86 * 10⁵ N/C
E)8.96 * 10^-22 N/C

Question 67

A + 8.0-nC point charge is located in the center of a thick conducting spherical shell.The shell has an inner radius of 1.0 m,an outer radius of 1.2 m,and a charge of -3.0 nC.What is the magnitude of the electric field at r = 1.1 m?

A)0 N/C
B)22 N/C
C)38 N/C
D)60 N/C
E)110 N/C

Question 68

Consider a cubical box that contains a charge distribution of total charge q = 6.40 $\mu$ C.The total electric flux through 5 of the 6 sides is $\varPhi$ = 3.90 *10⁵ Nm²/C.What is the electric flux through the remaining sixth surface of the box (in Nm²/C)?

A)3.33 * 10⁵
B)3.90 * 10⁵
C)4.56 * 10⁵
D)5.34 * 10⁵
E)6.24 * 10⁵

Question 69

What is the electric field (in N/C)at point A?

A)1.2 * 10⁵ up
B)1.2 * 10⁵ down
C)4.0 * 10⁵ up
D)4.0 * 10⁵ down
E)zero

Question 70

A + 8.0-nC point charge is located in the center of a thick conducting spherical shell.The shell has an inner radius of 1.0 m,an outer radius of 1.2 m,and a charge of -3.0 nC.What is the magnitude of the electric field at r = 0.5 m?

A)0 N/C
B)110 N/C
C)180 N/C
D)200 N/C
E)290 N/C

Question 71

A metal sphere of radius R = 12 cm carries a total charge of Q = 1 $\mu$ C.What is the magnitude of the electric field just outside the sphere?

A)1.25 N/C
B)425 N/C
C)85,200 N/C
D)625,000 N/C
E)1.25 * 10⁸ N/C

Question 72

A small charge of -11 $\mu$ C is in a constant vertical electric field E = 2.32 * 10³ N/C in the positive y-direction.If the acceleration of the charge is -0.80 m/s²,what is the mass of the charge? There is no gravity.

A)0.071 kg
B)0.041 kg
C)0.022 kg
D)0.050 kg
E)0.032 kg

Question 73

A small charge is in a constant vertical electric field E = 1.32 * 10³ N/C in the positive y-direction.If the charge has a mass of 0.022 kg and its acceleration is -1.0 m/s²,what is the charge? There is no gravity.

A)-11 $\mu$ C
B)-17 $\mu$ C
C)+11 $\mu$ C
D)+17 $\mu$ C
E)-21 $\mu$ C

Question 74

A + 8.0-nC point charge is located in the center of a thick conducting spherical shell.The shell has an inner radius of 1.0 m,an outer radius of 1.2 m,and a charge of -3.0 nC.What is the magnitude of the electric field at r = 1.5 m?

A)22 N/C
B)20 N/C
C)0 N/C
D)38 N/C
E)60 N/C