Skills Worksheet Concept Review Section Electric Charge and Force
Static Electricity Review
Navigate to:
[ #17 | #18 | #19 | #20 | #21 | #22 | #23 | #24 | #25 | #26 | #27 | #28 | #29 | #thirty | #31 | #32]
17. Which of the following charging methods work without always touching the object to exist charged to the object used to charge information technology? Choose all that apply.
| a. charging by friction | b. charging past contact | c. charging by consecration |
Respond: C
In charging by induction, a charged object is brought near an object without touching it. The presence of the accuse object induces electron movement and a polarization of the object. And so conducting pathway to ground is established and electron movement occurs between the object and the ground. During the process, the charged object is never touched to the object being charged.
18. Which of the post-obit charging methods result in charging an object reverse to the charge on the object used to charge it? Choose all that apply.
| a. charging by friction | b. charging past contact | c. charging past induction |
Answer: AC
In charging by friction, the two objects being rubbed acquire reverse types of accuse as electrons are transferred betwixt objects.
In charging by contact, both objects learn the same type of accuse.
In charging by consecration (as described in the respond to Question #17), the objects acquire the opposite blazon of charge.
19. Which of the following statements are true statements almost electric force? Choose all that apply.
- Electric force is a contact force.
- Electric forces can only deed between charged objects - either like-charged or oppositely-charged.
- Electric forces between two charged objects increases with increasing separation distance.
- Electrical forces between two charged objects increases with increasing quantity of charge on the objects.
- If object A attracts object B with an electrical forcefulness, then the attractive force must be mutual - i.e., object B also attracts object A with the same forcefulness.
- A doubling of the quantity of charge on one of the objects results in a doubling of the electrical force.
- A tripling of the quantity of charge on both of the objects results in an increase in the electric force past a factor of 6.
- A doubling of the separation distance betwixt ii signal charges results in a quadrupling of the electric force.
- A tripling of the separation distance between two indicate charges results in an electric force which is ane-6th of the original value.
Answer: DEF
a. Electric force is a not-contact force (or field forcefulness); it can human activity over separation distances even when the objects do not touch.
b. An electrical attraction can even occur between a charged object and a neutral object. The neutral object is first polarized and and then the attraction tin occur.
c. As separation distance increases, the electrical strength decreases; at that place is an inverse human relationship.
d. Every bit the charge on any of the 2 objects increases, the electrical force increases; at that place is a direct relationship.
e. Forces - even electric forces - come in pairs. For every activity, in that location is an equal and opposite reaction strength. Indeed, to say that "object A attracts object B" is to automatically infer that object B also attracts object A.
f. Whatever alteration is in fabricated of the accuse, the same alteration is made of the electric forcefulness. Doubling the charge will double the force.
g. Whatever alteration is in made of the charge, the same alteration is made of the electric force. Tripling the accuse will triple the force; tripling the other charge will triple the force again. Tripling the force (x3) two times volition have the net consequence of increasing the force by a cistron of ix (non vi).
h. Force is inversely proportional to the square of the distance. Whatever alteration is fabricated of the distance, the changed square alteration is fabricated of the force. So increasing altitude by a factor of 2 (doubling information technology) will decrease forcefulness by a gene of 4.
i. Force is inversely proportional to the foursquare of the distance. Whatever alteration is made of the altitude, the inverse square alteration is fabricated of the force. And then increasing distance by a cistron of 2 (doubling it) will subtract strength past a gene of 9 (three^ii).
twenty. Which of the following statements are truthful statements almost electric field? Choose all that utilise.
- The electric field strength created by object A is dependent upon the separation altitude from object A.
- The electric field strength created by object A is dependent upon the charge on object A.
- The electrical field strength created by object A is dependent upon the accuse of the test object used to measure out the strength of the field.
- The electric field strength almost charged Object A is the force per charge experienced by a test charge placed at some location about Object A.
- As the distance from Object A is doubled, the electric field strength created past object A increases by a factor of iv.
- As the charge of Object A is doubled, the electric field strength created by object A increases by a cistron of ii.
- As the charge of Object A is doubled and the distance from object A is doubled, the electric field strength created by object A decreases by a factor of 2.
- Object B is used to examination the electric field forcefulness about Object A; every bit the charge of Object B is doubled, the strength which information technology experiences is doubled but the electric field force remains the aforementioned.
- Object B is used to exam the electric field strength about Object A; as the separation distance between Object A and Object B is doubled, the strength which information technology experiences decreases by a cistron of four but the electric field strength remains the same.
- The electric field strength inside of a closed conducting object (east.g., inside the sphere of the Van de Graaff generator) is cypher.
- For irregularly shaped objects, the electric field force is greatest effectually points of highest curvature.
- The electric field is a vector which points in the management which a positive test accuse would be accelerated.
- Electric fields are directed in in regions around negatively-charged objects and outwards in regions around positively-charged objects.
- Units on electric field are Newtons/Coulomb (N/C).
Answer: ABDFGHJKLMN
a. TRUE The E vector depends upon two factors - the charge of the object creating the field and the separation distance from that charge.
b. TRUE The Eastward vector depends upon two factors - the charge of the object creating the field and the separation altitude from that charge.
c. False An object can exist used to measure the forcefulness of an electric field; such an object is called a exam accuse. The test charge encounters an electric force. The electrical field is the ratio of the force divided by the charge on the test charge. If the quantity of accuse on the examination charge is increased, the forcefulness is increased proportionately but the ratio remains the aforementioned.
d. TRUE An object can be used to measure the strength of an electric field; such an object is called a examination charge. The test charge encounters an electric force. The electric field is the ratio of the force divided by the charge on the test charge.
e. Faux The electric field force is inversely proportional to the square of the distance of separation from the charge. If the distance is increased past a factor of ii, then the Eastward is decreased by a factor of 4.
f. TRUE The electric field force is direct proportional to the quantity of charge on the object which creates the field. Doubling the charge (Q) will double the electric field forcefulness.
g. TRUE The electric field forcefulness is straight proportional to the quantity of accuse on the object which creates the field and inversely proportional to the square of the altitude of separation from that charge. Doubling the charge will have the effect of increasing the E by a factor of two; doubling the altitude will have the effect of decreasing the Eastward by a gene of 4. The combined effect of these two factors volition upshot in decreasing the Due east past a cistron of 2.
h. Truthful The electric field strength (E) created by object A does not depend upon the charge on the object used to examination it. The electrical field force (F) would be doubled past the doubling of the charge. Just the electric field strength (E) is the force per charge - twice the force on twice the charge yields the same electrical field strength.
i. FALSE The electrical field strength created past object A does depend on how far from object A that the examination charge is. Twice the separation distance means i-4th the electrical forcefulness (the changed square police force) and therefore ane-fourth of the electric field.
j. True This is a unique property of the electrical field inside a closed conductor.
k. TRUE This is another unique property of the electric field. This property explains how lightning rods work. Being pointed, the electric field strength is large effectually the points (parts of highest curvature).
l. Truthful This is the customary convention used to define the direction of the electric field around any charged object.
m. TRUE Because electric field management is defined every bit the direction which a positively-charged object would accelerate, the management would exist toward negatively charged objects (+ test charges are attracted) and away from positively-charged objects (+ examination charges are repelled).
northward. True Since electrical field is the force per charge exerted upon a test charge, the units would be force units per charge units - Newtons/Coulomb.
21. Which of the following statements are true statements about lightning rods? Choose all that utilise.
- Lightning rods are placed on homes to reduce the take chances of lightning harm to a dwelling house.
- Any metallic object which is placed on the roof of a home and grounded by an appropriate conducting pathway can serve as a lightning rod.
- About lightning rods are pointed equally a decorative feature.
- To be totally effective, a lightning rod must stretch high into the sky and draw charge from the everyman clouds past the method of contact.
- Lightning rods are capable of reducing the backlog charge buildup in clouds, a characteristic of dangerous thunderstorms.
- Charge is incapable of passing from clouds to a lightning rods since the air between the clouds and the lightning rod has an insulating consequence.
- The electric field force virtually the points of lightning rods are very high.
Answer: AG
a. TRUE The function of lightning rods is to divert charge around your dwelling to the ground in the event of a possible lightning strike.
b. FALSE If the lightning rod does not have the feature protrusion up into the air to a higher place the edifice information technology protects, and then it might fail to do what it does best - divert accuse around the building and preventing it from being conducted through the dwelling.
c. FALSE Lightning rods are pointed because the electric field around a sharply curved object is high and serves to ionize air around it; this provides a conducting pathway from the cloud to the basis. The pathway allows charge to slowly flow betwixt cloud and footing, thus preventing a sudden lightning discharge. In more than contempo years, scientists have found that a edgeless tip on the lightning round provides and equal if not greater measure of protection.
d. Imitation Lightning rods do non demand to contact the clouds to belch them. The strong electric fields around the points serves to turn air from an insulator to a usher (by ionizing particles in the air). This provides a conducting pathway between the cloud and the lightning rod.
e. FALSE This argument is a good description of the classical dissipation theory of lightning rods. It was in one case believed (beginning with Ben Frnaklin) that lightning rods served to misemploy or remove electrostatic accuse buildup in clouds by removing the charge gradually over fourth dimension. Scientists generally agree that that dissipation theory is not an authentic view of the role of lightning rods. Information technology is believed that lightning rods serve to divert electrostatic accuse effectually a home during a lightning strike.
f. Simulated If this were true, then there wouldn't be any lightning strikes. The role of the lightning rod is to really make the pathway betwixt the cloud and the ground more conductive past ionizing the air effectually the rod and providing a more conductive path from cloud to ground through the lightning rod.
thousand. TRUE This explains why lightning rods are frequently pointed. Though as discussed in more than detail in c. above, blunt-tipped lighning rods take been institute to provide equal or even greater protection as pointed-tip lightning rods.
22. Charged balloons are used to induce a charge upon neutral metal pop cans. Identify the type of backlog charge which would be present on cans One thousand, H, I, J, K, L, Thou, Due north and P every bit shown in the diagrams below.
a. positive
b. negative
c. neutral
Diagram Type of Charge on... I.
G: positive (A) H: negative (B)
2.
I: negative (B) J: positive (A)
II.
Thou: positive (A) L: negative (B)
M: positive (A)
Four.
N: negative (B) 5.
P: neutral (C)
Answer: See table to a higher place.
I. The presence of the negatively-charged airship repels electrons which are present in tin can G. Many of these electrons move into can H. This leaves tin G charged positively (information technology lost electrons) and can H charged negatively (information technology gained electrons).
Two. The presence of the negatively-charged balloon side by side to can J repels electrons which are nowadays in can J. Many of these electrons movement into can I. Similarly, the presence of the positively-charged balloon side by side to tin I will attract electrons present in both cans. This combined issue leaves can J to become charged positively (it lost electrons) and can I to become charged negatively (it gained electrons).
Three. The presence of negatively-charged balloons on each finish of the drove of cans causes electrons to exist repelled from the balloons. Many electrons leave the 2 cans on the ends and enter the can in the middle in society to distant themselves from the balloons. This leaves Can Fifty charged negatively (it gained electrons) and Cans M and Thou charged positively (they lost electrons).
Iv. The presence of the positively-charged airship volition attract electrons towards itself. There is a migration of electrons from the ground (paw) towards the balloon. This leaves can Northward charged negatively.
V. Electrons in can P will exist attracted to the positively-charged balloon. This will polarize the can. Only unless there is a source of electrons connected to can P, there is no fashion for the can to develop an overall charge. The can remains neutral.
23. In diagram IV of Question #22, the pop tin acquires the charge that information technology does because ___.
- electrons move from the balloon to the pop tin
- electrons motion from the pop tin to the balloon
- protons move from the airship to the pop tin
- protons motility from the pop can to the balloon
- electrons move from the popular can to the paw (footing)
- electrons move from the paw (ground) to the pop can
- protons move from the pop tin to the hand (footing)
- protons movement from the paw (footing) to the pop can
Answer: F
Whatever explanation which involves the movement of protons can be quickly ruled out since protons are leap in the nucleus and incapable of moving near during ordinary electrostatic experiments. Electrons cannot motion from the balloon to the popular tin can (nor vice versa) since there is no connecting path between these two objects. Air is a relatively practiced insulator and prevents the movement of accuse betwixt these two objects. What happens is that electrons in the hand sense the electric pull of the balloon and are drawn towards information technology, entering the pop tin can and imparting a negative accuse to information technology.
24. A negatively charged balloon will exist attracted to a neutral wooden cabinet due to polarization. Which one of the following diagrams all-time depict why this occurs?
Reply: D
The molecules of the wooden cabinet are neutral (which rules out diagrams A, B and E) yet polarized. The molecules polarize in such a way so as to brand its forward side well-nigh appealing to the airship. This means that the positive poles of the wood molecules are nearest the negative charge of the balloon. Just diagram D shows this orientation.
For Questions #25 - #27, place the type of charge on objects A-D based on the electric field lines shown for each configuration of charges.
a. positive
b. negative
c. neutral
| 25.  A is positive | 26.  B is negative |
| 27.  C is positive and D is negative. | |
Answer: Run across diagrams above.
The direction of an electric field is the management which a positively charged exam charge would be accelerated. The electric field lines point in this same management. As such, electrical field lines are ever directed away from + charges and towards - charges (or infinity) . From this principle, it tin be reasoned that A is positive, B is negative, C is positive and D is negative.
Office B: Diagramming and Analysis
28. A neutral conducting sphere is charged by induction using a positively-charged balloon. What will be the charge of the following sphere in pace e if steps a - d are followed? _________
Explain how the object acquires this accuse. Show the type and location of excess charge on the conducting sphere in each stride of the diagram (where appropriate).
Reply: Run into diagram above.
In b., the presence of the positively-charged balloon serves to polarize the sphere. Electrons in the sphere are fatigued towards the positively-charged balloon. This leaves a separation of accuse in the sphere, with the excess negative accuse on the left and the excess positive charge on the correct.
In c., the sphere is touched to ground and electrons from the ground are fatigued upwards and into the right side of the sphere. It is the presence of the + charge on the right side of the sphere which attracts these electrons to itself. At this indicate the sphere is charged negatively.
In d., this excess negative accuse is shown distributed on the left side of the sphere, still drawn towards the positively-charged balloon.
In east,. the balloon is pulled away and there is a motility of electrons about the sphere so that the excess negative accuse is uniformly distributed.
A negatively-charged balloon is held above (without touching) a neutral electroscope. The presence of the nearby balloon causes the needle of the electroscope to deflect.
a. Draw the location and blazon of backlog charges on the "polarized" neutral electroscope.
b. Explicate how the airship has induced the temporary charge upon the electroscope (i.e., draw the direction of electron motility).
Answer: See diagram at right.
The negative balloon repels electrons from the plate to the needle and base. Since like charges are repelled, electrons in the top of the electroscope (the plate) are repelled and forced downwards to the bottom of the electroscope (the needle and base). This causes the temporary separation of charge or polarization of the electroscope.
[ #17 | #xviii | #19 | #20 | #21 | #22 | #23 | #24 | #25 | #26 | #27 | #28 | #29 | #30 | #31 | #32]
xxx. Construct electric field lines around the post-obit configuration of charges. Include at least vi lines per charge.
Answer: See diagrams above
Electric field lines brainstorm at either infinity or a + charge and are drawn either to infinity or to - charges. Avert crossing lines. At the surface of charges, the lines should be directed radially inwards (for - charges) or radially outwards (for + charges).
31. Utilise an unbroken arrow to show the management of electron movement in the following situation. The pointer should extend from the source of the electrons to the final destination of the electrons.
| a. A positively charged balloon is touched to a neutral conducting sphere.  Electrons move from the sphere to the + balloon. | b. A glass rod is rubbed with a slice of wool. The wool has the greater electron affinity.  Electrons motility from the drinking glass rod to the wool. |
| c. A positively-charged balloon is held near a neutral conducting sphere. The sphere is then touched on the opposite side.  Electrons movement from the hand to the sphere. | d. A negatively-charged rod is held virtually a neutral conducting sphere. The sphere is touched on the opposite side.  Electrons move from the sphere to the hand. |
Answer: Encounter diagrams in a higher place.
In a, c, and d, the movement of electrons is governed by the principles that opposites attract and like-charged objects repel. Electrons (beingness negative) are attracted to positively charged objects and repelled by negatively charged objects.
In b, the more than electron-loving substance (highest electron affinity) gains the electrons from the object with which it is rubbed.
32. A negatively-charged object creates an electric field which can be measured at various locations in the region about it. An electric field vector is drawn for betoken X. Use your agreement of the electrical field - distance relationship to describe East vectors for points A - E. (The length of the arrow should exist indicative of the relative strength of the E vector.)
Respond: See diagram in a higher place.
The electric field vector points in the management which a positive test charge would be accelerated. This would result in a vector directed towards a negatively charged object. Thus all East vectors indicate towards the negatively-charged object. The E vector is inversely dependent upon square of the distance. Thus, the points which are farther away have the smallest E vectors.
Navigate to:
You lot Might Also Similar ...
Users of The Review Session are often looking for learning resources that provide them with practice and review opportunities that include built-in feedback and teaching. If that is what you're looking for, and then you might also like the following:
- The Reckoner Pad
The Computer Pad includes physics word problems organized by topic. Each problem is accompanied by a pop-up answer and an sound file that explains the details of how to arroyo and solve the problem. It'south a perfect resource for those wishing to improve their problem-solving skills.
Visit: The Estimator Pad Home | Calculator Pad - Static Electricity
- Minds On Physics the App Serial
Minds On Physics the App ("MOP the App") is a serial of interactive questioning modules for the educatee that is serious about improving their conceptual agreement of physics. Each module of the series covers a different topic and is farther cleaved downwardly into sub-topics. A "MOP experience" will provide a learner with challenging questions, feedback, and question-specific help in the context of a game-like environment. It is available for phones, tablets, Chromebooks, and Macintosh computers. It's a perfect resource for those wishing to refine their conceptual reasoning abilities. Role four of the serial includes topics in Static Electricity.
Visit: MOP the App Home || MOP the App - Part 4
Source: https://www.physicsclassroom.com/reviews/Static-Electricity/Static-Electricity-Review-Answers-2
0 Response to "Skills Worksheet Concept Review Section Electric Charge and Force"
Post a Comment