Physics Chapters 21 & 22

A 10-ohm resistor has a 5-A current in it. What is the voltage across the resistor? A) 5 V B) 10 V C) 15 V D) 20 V E) more than 20 V

E) more than 20 V

A coulomb of charge that passes through a 6-volt battery is given A) 6 joules. B) 6 amperes. C) 6 ohms. D) 6 watts. E) 6 newtons.

A) 6 joules.

Which statement is correct? A) Charge flows in a circuit. B) Voltage flows through a circuit. C) Resistance is established across a circuit. D) Current causes voltage.

A) Charge flows in a circuit.

In a common dc circuit, electrons move at speeds of A) a fraction of a centimeter per second. B) many centimeters per second. C) the speed of a sound wave. D) the speed of light. E) none of these.

A) a fraction of a centimeter per second.

Charges on the plates of a charged capacitor reside on the surfaces A) between the capacitor plates. B) exterior to the capacitor.

A) between the capacitor plates.

The electrical force between charges is strongest when the charges are A) close together. B) far apart. C) the electric force is constant everywhere.

A) close together.

A proton and an electron are placed in an electric field. Which undergoes the greater acceleration? A) electron B) proton C) both accelerate equally D) neither accelerates

A) electron

In an electrically neutral atom the number of protons in the nucleus is equal to the number of A) electrons that surround the nucleus. B) neutrons in the nucleus. C) both of these. D) neither of these.

A) electrons that surround the nucleus.

A positive charge and a negative charge held near each other are released. As they move, the force on each particle A) increases. B) decreases. C) stays the same.

A) increases.

Strip electrons from an atom and the atom becomes a A) positive ion. B) negative ion. C) different element.

A) positive ion.

When the distance between two charges is halved, the electrical force between the charges A) quadruples. B) doubles. C) halves. D) is reduced by 1/4. E) none of these.

A) quadruples.

Two charged particles held near each other are released. As they move, the acceleration of each decreases. Therefore, the particles have A) the same sign. B) opposite signs. C) not enough information given.

A) the same sign.

A woman experiences an electrical shock. The electrons making the shock come from the A) woman's body. B) ground. C) power plant. D) hairdryer. E) electric field in the air.

A) woman's body.

When a 10-V battery is connected to a resistor, the current in the resistor is 2 A. What is the resistor's value? A) 2 ohms B) 5 ohms C) 10 ohms D) 20 ohms E) more than 20 ohms

B) 5 ohms

The unit of electric charge, the coulomb, is the charge on A) one electron. B) a specific large number of electrons.

B) a specific large number of electrons.

In an ac circuit, the electric field A) increases via the inverse square law. B) changes magnitude and direction with time. C) is everywhere the same. D) is non-existent. E) none of these.

B) changes magnitude and direction with time.

An ampere is a unit of electrical A) pressure. B) current. C) resistance. D) all of these. E) none of these.

B) current.

To say that electric charge is quantized is to say that the charge on an object A) may occur in an infinite variety of quantities. B) is a whole-number multiple of the charge of one electron. C) will interact with neighboring electric charges. D) can be neither created nor destroyed.

B) is a whole-number multiple of the charge of one electron.

A wire that carries an electric current A) is electrically charged. B) may be electrically charged. C) is never electrically charged.

B) may be electrically charged.

If you comb your hair and the comb becomes positively charged, then your hair becomes A) positively charged. B) negatively charged. C) uncharged.

B) negatively charged.

Two charged particles held close to each other are released. As they move, the force on each particle increases. Therefore, the particles have A) the same sign. B) opposite signs. C) not enough information given.

B) opposite signs.

A main difference between gravitational and electric forces is that electrical forces A) attract. B) repel or attract. C) obey the inverse-square law. D) act over shorter distances. E) are weaker.

B) repel or attract.

The electric field inside an uncharged metal ball is zero. If the ball is negatively charged, the electric field inside the ball is then A) less than zero. B) zero. C) greater than zero.

B) zero.

Electrons are made to flow in a wire when there is A) an imbalance of charges in the wire. B) more potential energy at one end of the wire than the other. C) a potential difference across its ends.

C) a potential difference across its ends.

A transistor is an example of A) a resistor. B) a superconductor. C) a semiconductor. D) a dry cell. E) electrostatic shielding

C) a semiconductor.

The source of electrons lighting an incandescent ac light bulb is A) the power company. B) electrical outlet. C) atoms in the light bulb filament. D) the wire leading to the lamp. E) the source voltage.

C) atoms in the light bulb filament.

The electrical force between charges depends on the A) magnitude of electric charges. B) separation distance between electric charges. C) both of these. D) none of these.

C) both of these.

Electrons move in an electrical circuit A) by being bumped by other electrons. B) by colliding with molecules. C) by interacting with an established electric field. D) because the wires are so thin. E) none of these.

C) by interacting with an established electric field.

Which force binds atoms together to form molecules? A) gravitational B) nuclear C) electrical D) centripetal E) none of these

C) electrical

Heat a copper wire and its electric resistance A) decreases. B) remains unchanged. C) increases.

C) increases.

Stretch a copper wire so that it is thinner and the resistance between its ends A) decreases. B) remains unchanged. C) increases.

C) increases.

A wire carrying a current is normally charged A) negatively. B) positively. C) not at all.

C) not at all.

Two charged particles held close to each other are released. As the particles move, the velocity of each increases. Therefore, their charges have A) the same sign. B) opposite signs. C) not enough information given.

C) not enough information given.

A positive ion has more A) electrons than neutrons. B) electrons than protons. C) protons than electrons. D) protons than neutrons. E) neutrons than protons.

C) protons than electrons.

Particle A and Particle B interact with each other. Particle A has twice the charge of particle B. Compared to the force on Particle A, the force on Particle B is A) four times as much. B) two times as much. C) the same. D) half as much. E) none of these.

C) the same.

To say that electric charge is conserved is to say that electric charge A) may occur in an infinite variety of quantities. B) is a whole number multiple of the charge of one electron. C) will interact with neighboring electric charges. D) can be neither created nor destroyed.

D) can be neither created nor destroyed.

The fundamental force underlying all chemical reactions is A) gravitational. B) nuclear. C) centripetal. D) electrical. E) none of these.

D) electrical.

To say that electric charge is conserved means that no case has ever been found where A) the total charge on an object has changed. B) the net amount of negative charge on an object is unbalanced by a positive charge on another object. C) the total amount of charge on an object has increased. D) net charge has been created or destroyed. E) none of these.

D) net charge has been created or destroyed.

The source of electrons in an ordinary electrical circuit is A) a dry cell, wet cell or battery. B) the back emf of motors. C) the power station generator. D) the electrical conductor itself. E) none of these.

D) the electrical conductor itself.

An electron is pushed into an electric field where it acquires a 1-V electrical potential. If two electrons are pushed the same distance into the same electric field, the electrical potential of the two electrons is A) 0.25 V. B) 0.5 V. C) 1 V. D) 2 V. E) 4 V.

C) 1 V.

The current through a 10-ohm resistor connected to a 120-V power supply is A) 1 A. B) 10 A. C) 12 A. D) 120 A. E) none of these

C) 12 A.

The net charge on a charged capacitor A) depends on the area of the capacitor plates. B) depends on the distance between the capacitor plates. C) depends on the medium between the capacitor plates. D) all of these. E) none of these - the net charge is zero.

E) none of these - the net charge is zero.