Electricity Unit

A fuse or circuit breaker used in a circuit is usually inserted in parallel.

False

A material is a good insulator if outer electrons of atoms in the material are free to roam around.

False

A resistor is something placed in a circuit that totally blocks the flow of electrons.

False

An atom that is electrically polarized vibrates in only one direction.

False

Charge flows from low potential to high potential.

False

Coulomb's law says that there are two kinds of charges, positive and negative.

False

Electrical forces are strong, but in comparison, gravitational forces are stronger.

False

Electrical outlets in our walls are a source of electrons to run electrical appliances.

False

In a parallel circuit, current in each branch is the same.

False

In order to make a flashlight bulb light up, all you need to do is to run a wire from the positive terminal of a flashlight battery to the center of the bulb's base.

False

In solid conductors, positive current is the flow of protons in the conductor.

False

Most of the electricity we buy through power companies is direct current.

False

Ohm's law is a relationship among voltage, current, and charge.

False

One kilowatt-hour is equal to the energy consumed by an electric device of 1 W for 1 hour.

False

The direction of lines of force shows how large a force will be on a charge placed in an electric field.

False

The kilowatt-hour is a unit of power used by power companies.

False

The reason electrons are attracted to protons is that electrons and protons have the same amount of charge.

False

The unit of electric potential is the joule.

False

Using a 1-kW heater for one hour consumes more energy than using a 100-W bulb for one day.

False

When an object is charged by contact, electrons flow from the ground onto the object, or from the object onto the ground.

False

When you turn on a light, electrons move at speeds near the speed of light in order to light up the light bulb.

False

A bolt of lightning is a result of charging by induction.

True

A material that is a good insulator of electricity is normally a poor conductor of electricity.

True

A schematic diagram is a simplified, blocked-out picture of a circuit in which parts of the circuit are represented by symbols.

True

A voltage source is something that separates charges in a useful way.

True

All electrons are identical; all have exactly the same mass and charge.

True

Charge will move in a conductor when there is a difference in potential between the ends of the conductor.

True

Coulomb's law for electrical charges has the same mathematical form as Newton's law of gravitation.

True

Even though a car may be struck by lightning, people inside the car will normally be safe.

True

In a series circuit, the total voltage drop across a series of resistors is the sum of voltage drops across each individual resistor.

True

In materials such as metals, the outer shell electrons are loosely bound to the nuclei of their atoms and are free to move from one atom to another. These materials are good conductors.

True

In order to prevent overloading in a circuit, fuses are inserted in the circuit.

True

Semiconductors can be made to conduct electricity and they can also be made to act like good insulators.

True

The energy a charge possesses by virtue of its location is called electrical potential energy.

True

The study of electricity at rest is electrostatics.

True

The total amount of charge in the universe is constant. We have never observed a case of net creation or destruction of charge.

True

The unit of electric current is the ampere.

True

When a charge is placed in a region of space where there is an electric field, the charge will experience a force.

True

When charge moves in a circuit, it normally heats part of the circuit.

True

When light bulbs are connected in series, all carry the same current regardless of their resistances.

True

When resistors are arranged in parallel, their overall resistance is less than that of the smallest resistor.

True

When we allow charges to move onto or off a conductor by touching it with something connected to Earth, it is common to say that we are grounding it.

True

You can feel a slight shock from a 12-volt battery if your skin is moist.

True

You should never work with plugged-in electrical appliances while standing in water.

True

A 10.0-W resistor, 20.0-W resistor, and 25.0-W resistor are connected in series across a 110-V supply. Calculate the current in the circuit. a. 2.0 A b. 4.5 A c. 55 A d. 11 A

a. 2.0 A

In the circuit shown below, which bulb, when burned out, will cause all other bulbs to stop glowing? a. A b. B c. C d. F

a. A (can't see the picture lol)

In a series circuit, each circuit element has the same: a. Current b. Voltage c. Capacitance d. Resistance

a. Current

A negatively charged balloon sticks to a wooden door. However, an uncharged balloon does not stick to a wooden door. What is the nature of the charge on the wooden door? a. Electrically neutral b. Positively charged c. Conductor d. Lacking protons

a. Electrically neutral

The distance between two charges is r, and the force between them is F. What is the force between them if the distance between them is doubled? a. F/4 b. 4F c. 9F d. F/9

a. F/4

If a resistor is added to a parallel circuit, the equivalent resistance: a. Increases b. Decreases c. Remains the same d. Becomes zero

a. Increases

The number of current paths in a series circuit is: a. One b. Two c. Three d. Four

a. One

Which of the following materials is the best conductor of electricity? a.Wet skin b.Glass c.Dry air d.Rubber

a. Wet skin

Protons and electrons a. attract each other. b. repel each other. c. do not interact.

a. attract each other.

The fundamental force underlying all chemical reactions is a. electrical. b. gravitational. c. centripetal. d. nuclear. e. none of the above

a. electrical.

A 4.0-W resistor, an 8.0-W resistor, and a 10.0-W resistor are connected in series across an 11-V battery. What value of resistance must be connected in series with the circuit to decrease the current in the circuit by 50.0%? a. 11 W b. 22 W c. 33 W d. 44 W

b. 22 W

Three resistors of 1.00 ´ 102 W, 3.90 kW, and 1.00 kW are connected in series across a 2.00 ´ 102-V battery. The voltage drop across the resistor of value 1.00 kW is: a. 19.0 V b. 40.0 V c. 60.0 V d. 156 V

b. 40.0 V

When two bodies are charged, the total charge before and after charging remains the same because of: a. Quantization of charges b. Conservation of charges c. Law of induction d. Coulomb's law

b. Conservation of charges

If a resistor is added to a series circuit, the equivalent resistance: a. Increases b. Decreases c. Remains the same d. Becomes zero

b. Decreases

Electrical forces between charges are strongest when the charges are a. far apart. b. close together. c. The electrical force is constant everywhere.

b. close together.

The net charge of a nonionized atom a. depends only on the number of electrons it has. b. is zero. c. usually cannot be determined. d. depends only on the number of protons it has.

b. is zero

A positive ion has a. more electrons than protons. b. more protons than electrons. c. a +1 charge always. d. one proton.

b. more protons than electrons.

The charge of an electron is a. positive. b. negative. c. Electrons have no charge.

b. negative

The common hydrogen atom consists of a. one electron. b. one proton and one electron. c. one proton. d. two protons, one neutron, and two electrons. e. one neutron and one electron.

b. one proton and one electron.

Two like charges a. neutralize each other. b. repel each other. c. must be neutrons. d. attract each other. e. have no effect on each other.

b. repel each other.

A difference between electrical forces and gravitational forces is that electrical forces include a. infinite range. b. repulsive interactions. c. the inverse square law. d. separation distance. e. none of the above

b. repulsive interactions.

Three resistors of 10.0 W, 20.0 W, and 25.0 W are connected in parallel across a 100-V battery. What is the equivalent resistance of the circuit and the current flowing through the 10.0-W resistor? a. 0.190 W, 4 A b. 6.67 W, 5 A c. 5.26 W, 10 A d. 55.0 W, 20 A

c. 5.26 W, 10 A

A 4.0-W resistor, an 8.0-W resistor, and a 10.0-W resistor are connected in series across an 11-V battery. The total voltage drop across the 4.0-W and 8.0-W resistors is: a. 2.0 V b. 4.0 V c. 6.0 V d. 11 V

c. 6.0 V

What change is observed in the strength of an electric field around a charged object if the magnitude of the test charge is doubled? a. Electric field is doubled. b. Electric field is halved. c. Electric field remains unchanged. d. Electric field reduces to one-fourth of the original value.

c. Electric field remains unchanged.

When a conducting sphere is charged positively, initially the charge is deposited on the left side. However, due to the sphere's conducting nature, the charge spreads uniformly throughout the surface of the sphere. Charge is uniformly distributed because: a. Charged atoms at the location of charge distribute throughout the surface. b. Excess protons move from the location of charge to rest. c. Excess electrons within the sphere move toward excess protons. d. Excess charge within the sphere moves out into the ground from the surface.

c. Excess electrons within the sphere move toward excess protons.

Which of the following is true for the direction of an electric field? a. It is same as the direction of the force exerted on a negative test charge. b. It is opposite to the direction of the force exerted on a positive test charge. c. It is same as the direction of the force exerted on a positive test charge. d. It is opposite to the direction of the force exerted on a neutral test charge.

c. It is same as the direction of the force exerted on a positive test charge.

Three rods of different materials P, Q, and R, are charged by various methods. When the rods are brought near each other, the rods P and Q repel each other, while the rods P and R attract each other. Which of the following could be the signs of the charges on the rods? Rod P Rod Q Rod R a. - + - b. - + - c. - - + d. - - -

c. Rod P: - Rod Q: - Rod R: +

Coulomb's law says that the force between any two charges depends a. directly on the size of the charges. b. inversely on the square of the distance between the charges. c. both A and B d. none of the above

c. both A and B

If you comb your hair and the comb becomes positively charged, your hair becomes a. uncharged. b. positively charged. c. negatively charged.

c. negatively charged.

Which of the following statements is true about electric forces? a.Electric forces cause objects to only attract each other. b.Electric forces cause objects to only repel each other. c.Electric forces cause objects to repel or attract each other. d.Electric forces have no effect on each other.

c.Electric forces cause objects to repel or attract each other.

A 20.0-W resistor and a 40.0-W resistor are connected in series across a battery. If the current is 2.00 A, what is the voltage of the battery? a. 30.0 V b. 60.0 V c. 80.0 V d. 1.20 x 10^2 V

d. 1.20 x 10^2 V

A 2.00-W resistor and a 12.0-W resistor are connected in parallel across a 20.0-V battery. What is the current flowing through the 2.00-W resistor? a. 1.67 A b. 1.40 A c. 11.6 A d. 10.0 A

d. 10.0 A

Four resistors of 10.0 W each are connected in parallel. A combination of four resistors of 10.0 W each is connected in series along with the parallel arrangement. What is the equivalent resistance of the circuit? a. 80.0 W b. 40.4 W c. 40.0 W d. 42.5 W

d. 42.5 W

To say that electric charge is conserved means that no case has ever been found where a. the total amount of charge on an object has increased. b. one object has more charge than another object. c. the total charge on an object has changed. d. net charge has been created or destroyed. e. none of the above

d. net charge has been created or destroyed.

Two charges are separated by a certain distance. If the magnitude of each charge is doubled, the force on each charge is a. halved. b. doubled. c. tripled. d. quadrupled.

d. quadrupled.

When the distance between two charges is halved, the electrical force between the charges a. doubles. b. reduces to one fourth. c. halves. d. quadruples. e. none of the above

d. quadruples.

Conservation of charge means that a. the total amount of charge in the universe is constant. b. no experimenter has ever seen a single charge destroyed by itself. c. electrons by themselves can be neither created nor destroyed. d. charge can be neither created nor destroyed. e. all of the above

e. all of the above

Atomic nuclei of almost all elements consist of a. only neutrons. b. protons and electrons. c. neutrons and electrons. d. only protons. e. protons and neutrons.

e. protons and neutrons.