Question 1

If the size of the charge value is doubled for both of two point charges maintained at a constant separation,the mutual force between them will be changed by what factor?

Accepted Answer

A)  4 
B)  2 
C)  1/2 
D)  1/4 
E)  ​1

Question 2

A 6.64 μC charge is placed at the origin and a second charge is placed on the x-axis at x = 0.2 m.If the resulting force on the second charge is 6.4 N in the positive x-direction,what is the force on the charge at the origin?
​

Accepted Answer

A)  6.4 N in the positive x-direction 
B)  6.4 N in the negative x-direction 
C)  0 N 
D)  not able to be determined until the second charge is known 
E)  ​6.4 N in the negative y-direction

Question 3

Object A has a charge q on it,object B has a charge q on it,and object C has a charge 4q on it.These charges are arranged,one each,at the vertices of an equilateral triangle.Which charge has the greatest magnitude electric force on it?
​

Accepted Answer

A)  A 
B)  B 
C)  C 
D)  All have equal magnitude forces on them. 
E)  ​A and B

Question 4

Doug rubs a piece of fur on a hard rubber rod,giving the rod a negative charge.What happens?

Accepted Answer

A)  Protons are removed from the rod. 
B)  Electrons are added to the rod. 
C)  The fur is also charged negatively. 
D)  The fur is left neutral.

Question 5

An uncharged conductor is supported by an insulating stand.I pass a positively charged rod near the left end of the conductor,but do not touch it.The right end of the conductor will be:

Accepted Answer

A)  negative. 
B)  positive. 
C)  neutral. 
D)  attracted.

Question 6

Charges q,q,and -q are placed on the x-axis at x = 0,x = 6 m,and x = 12 m,respectively.At which of the following points does the electric field have the greatest magnitude?
​

Accepted Answer

A)  x = 5 m 
B)  x = 9 m 
C)  x = 14 m 
D)  The electric field has the same magnitude at all three positions. 
E)  ​x = 11 m

Question 7

Two point charges are separated by 12.0 cm and have charges of +5.00 µC and −5.00 µC,respectively.What is the electric field at a point midway between the two charges? (ke = 8.99 × 109 N·m2/C2)

Accepted Answer

A)  3.75 × 106 N/C 
B)  2.5 × 107 N/C 
C)  1.75 × 106 N/C 
D)  ​2.13 × 108 N/C 
E)  ​zero

Question 8

Two identical balls have the same amount of charge,but the charge on ball A is positive and the charge on ball B is negative.The balls are placed on a smooth,level,frictionless table whose top is an insulator.Which of the following is true?

Accepted Answer

A)  Since the force on A is equal but opposite to the force on B,they will not move. 
B)  They will move together with constant acceleration. 
C)  Since the force on both balls is negative,they will move in the negative direction. 
D)  None of the above is correct.

Question 9

Two point charges,separated by 1.5 cm,have charge values of +2.0 and −4.0 µC,respectively.What is the value of the mutual force between them? (ke = 8.99 × 109 N⋅m2/C2)

Accepted Answer

A)  72 N 
B)  1.4 × 10−8 N 
C)  5.0 × 10−12 N 
D)  0.7 × 10−3 N 
E)  ​86 N

Question 10

Two small objects are suspended from threads.When the objects are moved close together,they attract one another.Which of the following could produce this result?

Accepted Answer

A)  One object is positively charged and the other is negatively charge. 
B)  One object is positively charged and the other is uncharged. 
C)  One object is negatively charged and the other is uncharged. 
D)  All of the above could result in such attraction.

Question 11

Which of the following best characterizes electrical insulators?

Accepted Answer

A)  charges on the surface don't move 
B)  high tensile strength 
C)  electric charges move freely 
D)  good heat conductors

Question 12

Charges of 2.3 µC and −7 µC are placed at two corners of an equilateral triangle with sides of 0.1 m.At the third corner,what is the electric field magnitude created by these two charges? (ke = 8.99 × 109 N·m2/C2)
​

Accepted Answer

A)  11.1 × 106 N/C 
B)  2.8 × 106 N/C 
C)  5 × 106 N/C 
D)  5.6 × 106 N/C 
E)  ​7.4 × 106 N/C

Question 13

We have an initially uncharged hollow metallic sphere with radius of 5.0 cm.I place a small object with a charge of +26 µC at the center of the sphere through a hole in the surface.Find the electric field present at a point 10 cm from the sphere's center.(ke = 8.99 × 109 N⋅m2/C2)
​

Accepted Answer

A)  46.7 × 106 N/C 
B)  11.7 × 106 N/C 
C)  23.4 × 106 N/C 
D)  5.8 × 106 N/C 
E)  ​35.1 × 106 N/C

Question 14

About how many electrons are in 190 grams of water (H2O)?

Accepted Answer

A)  1026 
B)  1023 
C)  1021 
D)  1027 
E)  ​1025

Question 15

We have a hollow metallic sphere with charge −5.9 µC and radius 5 cm.We insert a +10-µC charge at the center of the sphere through a hole in the surface.What charge now rests on the outer surface of the sphere?
​

Accepted Answer

A)  +4.1 µC 
B)  +15.9 µC 
C)  -4.1 µC 
D)  -15.9 µC 
E)  ​-10 µC

Question 16

If the distance between two point charges is doubled,the mutual force between them will be changed by what factor?

Accepted Answer

A)  4 
B)  2 
C)  1/2 
D)  1/4 
E)  ​1

Question 17

Two equal charges,each Q,are separated by some distance.What third charge would need to be placed half way between the two charges so that the net force on each charge would be zero?

Accepted Answer

A)  −Q 
B)  −Q/2 
C)  −Q/4 
D)  −Q/8

Question 18

If body P,with a positive charge,is placed in contact with body Q (initially uncharged),what will be the nature of the charge left on Q?

Accepted Answer

A)  must be equal in magnitude to that on P 
B)  must be negative 
C)  must be positive 
D)  must be greater in magnitude than that on P

Question 19

A spherical surface surrounds a point charge it its center.If the charge is doubled and if the radius of the surface is also doubled,what happens to the electric flux ΦE out of the surface and the magnitude E of the electric field at the surface as a result of these doublings?

Accepted Answer

A)  ΦE and E do not change. 
B)  ΦE increases and E remains the same. 
C)  ΦE increases and E decreases. 
D)  ΦE increases and E increases.

Question 20

A 6.2 μC charge is placed at the origin and a second charge is placed on the x-axis at x = 0.1 m.If the resulting force on the second charge is 5.2 N in the positive x-direction,what is the value of its charge?
​

Accepted Answer

A)  0.9 μC 
B)  0.9 nC 
C)  -0.9 μC 
D)  -0.9 nC 
E)  ​0 μC

Exam 15: Electric Forces and Electric Fields

If the size of the charge value is doubled for both of two point charges maintained at a constant separation,the mutual force between them will be changed by what factor?

A 6.64 μC charge is placed at the origin and a second charge is placed on the x-axis at x = 0.2 m.If the resulting force on the second charge is 6.4 N in the positive x-direction,what is the force on the charge at the origin?

Object A has a charge q on it,object B has a charge q on it,and object C has a charge 4q on it.These charges are arranged,one each,at the vertices of an equilateral triangle.Which charge has the greatest magnitude electric force on it?

Doug rubs a piece of fur on a hard rubber rod,giving the rod a negative charge.What happens?

An uncharged conductor is supported by an insulating stand.I pass a positively charged rod near the left end of the conductor,but do not touch it.The right end of the conductor will be:

Charges q,q,and -q are placed on the x-axis at x = 0,x = 6 m,and x = 12 m,respectively.At which of the following points does the electric field have the greatest magnitude?

Two point charges are separated by 12.0 cm and have charges of +5.00 µC and −5.00 µC,respectively.What is the electric field at a point midway between the two charges? (k_e = 8.99 × 10⁹ N·m²/C²)

Two identical balls have the same amount of charge,but the charge on ball A is positive and the charge on ball B is negative.The balls are placed on a smooth,level,frictionless table whose top is an insulator.Which of the following is true?

Two point charges,separated by 1.5 cm,have charge values of +2.0 and −4.0 µC,respectively.What is the value of the mutual force between them? (k_e = 8.99 × 10⁹ N⋅m²/C²)

Two small objects are suspended from threads.When the objects are moved close together,they attract one another.Which of the following could produce this result?

Which of the following best characterizes electrical insulators?

Charges of 2.3 µC and −7 µC are placed at two corners of an equilateral triangle with sides of 0.1 m.At the third corner,what is the electric field magnitude created by these two charges? (k_e = 8.99 × 10⁹ N·m²/C²)

We have an initially uncharged hollow metallic sphere with radius of 5.0 cm.I place a small object with a charge of +26 µC at the center of the sphere through a hole in the surface.Find the electric field present at a point 10 cm from the sphere's center.(k_e = 8.99 × 10⁹ N⋅m²/C²)

About how many electrons are in 190 grams of water (H₂O) ?

We have a hollow metallic sphere with charge −5.9 µC and radius 5 cm.We insert a +10-µC charge at the center of the sphere through a hole in the surface.What charge now rests on the outer surface of the sphere?

If the distance between two point charges is doubled,the mutual force between them will be changed by what factor?

Two equal charges,each Q,are separated by some distance.What third charge would need to be placed half way between the two charges so that the net force on each charge would be zero?

If body P,with a positive charge,is placed in contact with body Q (initially uncharged) ,what will be the nature of the charge left on Q?

A spherical surface surrounds a point charge it its center.If the charge is doubled and if the radius of the surface is also doubled,what happens to the electric flux Φ_E out of the surface and the magnitude E of the electric field at the surface as a result of these doublings?

A 6.2 μC charge is placed at the origin and a second charge is placed on the x-axis at x = 0.1 m.If the resulting force on the second charge is 5.2 N in the positive x-direction,what is the value of its charge?

Exam 15: Electric Forces and Electric Fields

If the size of the charge value is doubled for both of two point charges maintained at a constant separation,the mutual force between them will be changed by what factor?

A 6.64 μC charge is placed at the origin and a second charge is placed on the x-axis at x = 0.2 m.If the resulting force on the second charge is 6.4 N in the positive x-direction,what is the force on the charge at the origin? ​

Object A has a charge q on it,object B has a charge q on it,and object C has a charge 4q on it.These charges are arranged,one each,at the vertices of an equilateral triangle.Which charge has the greatest magnitude electric force on it? ​

Doug rubs a piece of fur on a hard rubber rod,giving the rod a negative charge.What happens?

An uncharged conductor is supported by an insulating stand.I pass a positively charged rod near the left end of the conductor,but do not touch it.The right end of the conductor will be:

Charges q,q,and -q are placed on the x-axis at x = 0,x = 6 m,and x = 12 m,respectively.At which of the following points does the electric field have the greatest magnitude? ​

Two point charges are separated by 12.0 cm and have charges of +5.00 µC and −5.00 µC,respectively.What is the electric field at a point midway between the two charges? (ke = 8.99 × 109 N·m2/C2)

Two identical balls have the same amount of charge,but the charge on ball A is positive and the charge on ball B is negative.The balls are placed on a smooth,level,frictionless table whose top is an insulator.Which of the following is true?

Two point charges,separated by 1.5 cm,have charge values of +2.0 and −4.0 µC,respectively.What is the value of the mutual force between them? (ke = 8.99 × 109 N⋅m2/C2)

Two small objects are suspended from threads.When the objects are moved close together,they attract one another.Which of the following could produce this result?

Which of the following best characterizes electrical insulators?

Charges of 2.3 µC and −7 µC are placed at two corners of an equilateral triangle with sides of 0.1 m.At the third corner,what is the electric field magnitude created by these two charges? (ke = 8.99 × 109 N·m2/C2) ​

We have an initially uncharged hollow metallic sphere with radius of 5.0 cm.I place a small object with a charge of +26 µC at the center of the sphere through a hole in the surface.Find the electric field present at a point 10 cm from the sphere's center.(ke = 8.99 × 109 N⋅m2/C2) ​

About how many electrons are in 190 grams of water (H2O) ?

We have a hollow metallic sphere with charge −5.9 µC and radius 5 cm.We insert a +10-µC charge at the center of the sphere through a hole in the surface.What charge now rests on the outer surface of the sphere? ​

If the distance between two point charges is doubled,the mutual force between them will be changed by what factor?

Two equal charges,each Q,are separated by some distance.What third charge would need to be placed half way between the two charges so that the net force on each charge would be zero?

If body P,with a positive charge,is placed in contact with body Q (initially uncharged) ,what will be the nature of the charge left on Q?

A spherical surface surrounds a point charge it its center.If the charge is doubled and if the radius of the surface is also doubled,what happens to the electric flux ΦE out of the surface and the magnitude E of the electric field at the surface as a result of these doublings?

A 6.2 μC charge is placed at the origin and a second charge is placed on the x-axis at x = 0.1 m.If the resulting force on the second charge is 5.2 N in the positive x-direction,what is the value of its charge? ​

A 6.64 μC charge is placed at the origin and a second charge is placed on the x-axis at x = 0.2 m.If the resulting force on the second charge is 6.4 N in the positive x-direction,what is the force on the charge at the origin?

Object A has a charge q on it,object B has a charge q on it,and object C has a charge 4q on it.These charges are arranged,one each,at the vertices of an equilateral triangle.Which charge has the greatest magnitude electric force on it?

Charges q,q,and -q are placed on the x-axis at x = 0,x = 6 m,and x = 12 m,respectively.At which of the following points does the electric field have the greatest magnitude?

Two point charges are separated by 12.0 cm and have charges of +5.00 µC and −5.00 µC,respectively.What is the electric field at a point midway between the two charges? (k_e = 8.99 × 10⁹ N·m²/C²)

Two point charges,separated by 1.5 cm,have charge values of +2.0 and −4.0 µC,respectively.What is the value of the mutual force between them? (k_e = 8.99 × 10⁹ N⋅m²/C²)

Charges of 2.3 µC and −7 µC are placed at two corners of an equilateral triangle with sides of 0.1 m.At the third corner,what is the electric field magnitude created by these two charges? (k_e = 8.99 × 10⁹ N·m²/C²)

We have an initially uncharged hollow metallic sphere with radius of 5.0 cm.I place a small object with a charge of +26 µC at the center of the sphere through a hole in the surface.Find the electric field present at a point 10 cm from the sphere's center.(k_e = 8.99 × 10⁹ N⋅m²/C²)

About how many electrons are in 190 grams of water (H₂O) ?

We have a hollow metallic sphere with charge −5.9 µC and radius 5 cm.We insert a +10-µC charge at the center of the sphere through a hole in the surface.What charge now rests on the outer surface of the sphere?

A spherical surface surrounds a point charge it its center.If the charge is doubled and if the radius of the surface is also doubled,what happens to the electric flux Φ_E out of the surface and the magnitude E of the electric field at the surface as a result of these doublings?

A 6.2 μC charge is placed at the origin and a second charge is placed on the x-axis at x = 0.1 m.If the resulting force on the second charge is 5.2 N in the positive x-direction,what is the value of its charge?