Question 1

When a hard rubber rod is given a negative charge by rubbing it with wool:

Accepted Answer

When a hard rubber rod is rubbed with wool, electrons (negative charges) are transferred from the wool to the rod, thereby giving the rod a negative charge. So, the best choice is D - negative charges are transferred from wool to rod.

Question 2

Consider the following procedural steps:  To charge an electroscope by induction, use the sequence:

Accepted Answer

B

Question 3

An electrical insulator is a material:

Accepted Answer

An electrical insulator is a material through which electrons do not flow easily. Insulators have high resistivity and low conductivity, meaning that they impede the flow of electrical current.

Question 4

The charge on a glass rod which has been rubbed with silk is called positive:

Accepted Answer

Charge is a property of matter, and its polarity (positive or negative) depends on the transfer of electrons between materials. The charge on a glass rod rubbed with silk is conventionally called positive, even though it actually involves the transfer of electrons from the glass to the silk, leaving the glass with a net negative charge. This convention was established historically and is widely used in the field of electrostatics.

Question 5

A negatively charged rubber rod is brought near the knob of a positively charged electroscope.The result is that:

Accepted Answer

The answer of A negatively charged rubber rod is brought...

Question 6

Two small charged objects repel each other with a force F when separated by a distance d.If the charge on each object is reduced to one-fourth of its original value and the distance between them is reduced to d/2 the force becomes:

Accepted Answer

The force between two charged objects is given by Coulomb's Law, which states that F=k(q1q2/d^2), where k is the Coulomb's constant.

If the charge on each object is reduced to one-fourth of its original value, the new force will be F' = k[(1/4)q1][(1/4)q2]/d^2 = (1/16)k(q1q2/d^2).

If the distance between the objects is reduced to d/2, the new force will be F''= kq1q2/(d/2)^2 = 4k(q1q2/d^2).

Combining F' and F'' we get the new force: F_new = F'+F'' = (1/16)k(q1q2/d^2) + 4k(q1q2/d^2) = (65/16)k(q1q2/d^2), which can be simplified to F_new = F/4.

Therefore, the force becomes F/4 when the charge on each object is reduced to one-fourth of its original value and the distance between them is reduced to d/2.

Question 7

A conductor is distinguished from an insulator with the same number of atoms by the number of:

Accepted Answer

The main difference between a conductor and an insulator is the ability to conduct electricity. Conductors have a large number of free electrons that can move easily through the material, while insulators have few free electrons. Therefore, the best choice is C, which mentions "nearly free electrons."

Question 8

A positively charged insulating rod is brought close to an object that is suspended by a string.If the object is repelled away from the rod we can conclude:

Accepted Answer

Like charges repel each other, so if the object is repelled by a positively charged rod, it indicates that the object is also positively charged.

Question 9

The diagram shows a pair of highly charged plastic cubes that attract each other.  Cube 3 is a conductor and is uncharged.Which of the following illustrates the forces between cubes1 and 3 and between cubes 2 and 3?

Accepted Answer

The answer of The diagram shows a pair of highly...

Question 10

Two particles, X and Y, are 4 m apart.X has a charge of 2Q and Y has a charge of Q.The force of X on Y:

Accepted Answer

According to Newton's third law of motion and Coulomb's law, the force between two charges is equal in magnitude and opposite in direction, regardless of the magnitude of the charges. Therefore, the force of X on Y is equal in magnitude to the force of Y on X.

Question 11

The diagram shows two pairs of highly charged plastic cubes.Cubes 1 and 2 attract each and cubes 1 and 3 repel each other.  Which of the following illustrates the forces of cube 2 on 3 and cube 3 on 2?

Accepted Answer

The answer of The diagram shows two pairs of highly...

Question 12

An electroscope is charged by induction using a glass rod that has been made positive by rubbing it with silk.The electroscope leaves:

Accepted Answer

When a positively charged glass rod is brought near an electroscope, the electroscope's leaves gain electrons from the ground to neutralize the effect of the positive charge near them, resulting in the electroscope itself becoming negatively charged. Protons do not move as they are part of the nucleus of atoms.

Question 13

A positively charged insulating rod is brought close to an object that is suspended by a string.If the object is attracted toward the rod we can conclude:

Accepted Answer

The answer of A positively charged insulating rod is brought...

Question 14

The leaves of a positively charged electroscope diverge more when an object is brought near the knob of the electroscope.The object must be:

Accepted Answer

When a positively charged object is brought near the knob of the electroscope, some of its positive charge is transferred to the leaves, causing them to repel each other and diverge. This can only happen if the object is positively charged. A negatively charged object would cause the leaves to come closer together, while an uncharged object or an insulator would have no effect on the leaves. Conductivity is not a determining factor in this scenario.

Question 15

A small object has charge Q.Charge q is removed from it and placed on a second small object.The two objects are placed 1 m apart.For the force that each object exerts on the other to be a maximum, q should be:

Accepted Answer

The force between the two objects is given by Coulomb's law, F = kQq/d^2, where k is the Coulomb constant and d is the distance between the two objects. To maximize the force, we want to maximize Qq. This occurs when q = Q/2, as (Q/2)^2 = Q(q-Q/2)/d^2 is a maximum. Therefore, the answer is C.

Question 16

A charged insulator can be discharged by passing it just above a flame.This is because the flame:

Accepted Answer

The flame contains ions, which can neutralize the charged insulator by transferring electrons.

Question 17

The units of 1/4 $\pi$$\varepsilon$₀ are:

Accepted Answer

1/4F1F1F1S1F1F1F10F1F1F1S1F1F1F10₀ can be rewritten as (1/4)*(F1F1F1S1)*(F1F1F10)*(F1F1F1S1)*(F1F1F10)*(_0)*(). From the given units, we know that F represents Farad (unit of capacitance), S represents Siemens (unit of conductance), U represents micro (10^-6), B represents tesla (unit of magnetic flux density), P represents pascal (unit of pressure), N represents newton (unit of force), C represents coulomb (unit of electric charge), and m represents meter (unit of length). So, the unit of (F1F1F1S1) is (Farad)^3*(Siemens), the unit of (F1F1F10) is (Farad)^10*(micro)^, the unit of (F1F1F1S1) is (Farad)^3*(Siemens), the unit of (F1F1F10) is (Farad)^10*(micro)^(-1), the unit of (_{0) is (Siemens)*(micro)*(tesla), and the unit of (}) is (Siemens)*(tesla). Multiplying all these units, we get the unit of the given expression as (Farad)^14*(micro)^(-1)*(Siemens)^4*(tesla). Therefore, the correct units for the given expression are NF1F1F1S1F1F1F10m² / C², which is option D.

Question 18

To make an uncharged object have a positive charge:

Accepted Answer

To make an uncharged object have a positive charge, some of its electrons must be removed. This will leave the object with a deficit of negative charges and therefore a positive charge.

Question 19

A neutral metal ball is suspended by a string.A positively charged insulating rod is placed near the ball, which is observed to be attracted to the rod.This is because:

Accepted Answer

The answer of A neutral metal ball is suspended by...

Question 20

To make an uncharged object have a negative charge we must:

Accepted Answer

Adding electrons to an uncharged object increases its negative charge because electrons carry a negative charge.

Quiz 21: Electric Charge

When a hard rubber rod is given a negative charge by rubbing it with wool:

Consider the following procedural steps: To charge an electroscope by induction, use the sequence:

An electrical insulator is a material:

The charge on a glass rod which has been rubbed with silk is called positive:

A negatively charged rubber rod is brought near the knob of a positively charged electroscope.The result is that:

Two small charged objects repel each other with a force F when separated by a distance d.If the charge on each object is reduced to one-fourth of its original value and the distance between them is reduced to d/2 the force becomes:

A conductor is distinguished from an insulator with the same number of atoms by the number of:

A positively charged insulating rod is brought close to an object that is suspended by a string.If the object is repelled away from the rod we can conclude:

The diagram shows a pair of highly charged plastic cubes that attract each other. Cube 3 is a conductor and is uncharged.Which of the following illustrates the forces between cubes1 and 3 and between cubes 2 and 3?

Two particles, X and Y, are 4 m apart.X has a charge of 2Q and Y has a charge of Q.The force of X on Y:

The diagram shows two pairs of highly charged plastic cubes.Cubes 1 and 2 attract each and cubes 1 and 3 repel each other. Which of the following illustrates the forces of cube 2 on 3 and cube 3 on 2?

An electroscope is charged by induction using a glass rod that has been made positive by rubbing it with silk.The electroscope leaves:

A positively charged insulating rod is brought close to an object that is suspended by a string.If the object is attracted toward the rod we can conclude:

The leaves of a positively charged electroscope diverge more when an object is brought near the knob of the electroscope.The object must be:

A small object has charge Q.Charge q is removed from it and placed on a second small object.The two objects are placed 1 m apart.For the force that each object exerts on the other to be a maximum, q should be:

A charged insulator can be discharged by passing it just above a flame.This is because the flame:

The units of 1/4 $\pi$ $\varepsilon$ ₀ are:

To make an uncharged object have a positive charge:

A neutral metal ball is suspended by a string.A positively charged insulating rod is placed near the ball, which is observed to be attracted to the rod.This is because:

To make an uncharged object have a negative charge we must:

Quiz 21: Electric Charge

When a hard rubber rod is given a negative charge by rubbing it with wool:

Consider the following procedural steps: To charge an electroscope by induction, use the sequence:

An electrical insulator is a material:

The charge on a glass rod which has been rubbed with silk is called positive:

A negatively charged rubber rod is brought near the knob of a positively charged electroscope.The result is that:

Two small charged objects repel each other with a force F when separated by a distance d.If the charge on each object is reduced to one-fourth of its original value and the distance between them is reduced to d/2 the force becomes:

A conductor is distinguished from an insulator with the same number of atoms by the number of:

A positively charged insulating rod is brought close to an object that is suspended by a string.If the object is repelled away from the rod we can conclude:

The diagram shows a pair of highly charged plastic cubes that attract each other. Cube 3 is a conductor and is uncharged.Which of the following illustrates the forces between cubes1 and 3 and between cubes 2 and 3?

Two particles, X and Y, are 4 m apart.X has a charge of 2Q and Y has a charge of Q.The force of X on Y:

The diagram shows two pairs of highly charged plastic cubes.Cubes 1 and 2 attract each and cubes 1 and 3 repel each other. Which of the following illustrates the forces of cube 2 on 3 and cube 3 on 2?

An electroscope is charged by induction using a glass rod that has been made positive by rubbing it with silk.The electroscope leaves:

A positively charged insulating rod is brought close to an object that is suspended by a string.If the object is attracted toward the rod we can conclude:

The leaves of a positively charged electroscope diverge more when an object is brought near the knob of the electroscope.The object must be:

A small object has charge Q.Charge q is removed from it and placed on a second small object.The two objects are placed 1 m apart.For the force that each object exerts on the other to be a maximum, q should be:

A charged insulator can be discharged by passing it just above a flame.This is because the flame:

The units of 1/4 π\piπε\varepsilonε 0 are:

To make an uncharged object have a positive charge:

A neutral metal ball is suspended by a string.A positively charged insulating rod is placed near the ball, which is observed to be attracted to the rod.This is because:

To make an uncharged object have a negative charge we must:

The units of 1/4 $\pi$ $\varepsilon$ ₀ are: