Unit 7 Physics Test

Which of the following circuits can be used to measure the resistance of the heating element, shown as a resistor in the diagrams below?

A in series V in the parallel circuit

To say that electric charge is conserved is to say that electric charge

can be neither created nor destroyed.

In a series circuit, each circuit element has the same:

circuit

An automatic switch that opens when the current reaches a set value is called:

circuit breaker

The electrical force between charges is strongest when the charges are

close together

When two bodies are charged, the total charge before and after charging remains the same because of:

conservation charges

If a resistor is added to a parallel circuit, the equivalent resistance:

decrease

The electric field inside the dome of a Van de Graaff generator

depends on the amount of charge the outside of dome. depends on the volume of the dome Choices A and B are both correct. None of the other choices are correct.. <------------

Particle A has twice the charge of nearby particle B. Compared to the force on Particle A, the force on Particle B is

same

Sphere A carries a net positive charge, and sphere B is neutral. They are placed near each other on an insulated table. Sphere B is briefly touched with a wire that is grounded. Which statement is correct?

Sphere B is now negatively charged,

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.

- - +

Ideally, the resistance of an ammeter should be:

0

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?

1.20 x 10^2 V

A circuit consists of two resistors, Ra and Rb, connected in series with a 20-V battery. What should be the ratio of so that the voltage drop across Rb is 18 V?

1/9

A 120-V source supplies current to a parallel combination of a television set of 60.0-W resistance and a 1.0 ´ 103-W electric kettle. The power source is connected in series with a 20.0-A fuse. A third device is connected in parallel with the television set. What is the minimum resistance that the device can have without melting the fuse?

12W

The distance between two charges and is r, and the force between them is F. What is the force between them if the distance between them is quartered?

16F

Two charges separated by one meter exert 1-N forces on each other. If the charges are pushed to 1/4 meter separation, the force on each charge will be

16N

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.

2.0 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. What value of resistance must be connected in series with the circuit to decrease the current in the circuit by 50.0%?

22W

A 15.0-W resistor and a 20.0-W resistor are connected in parallel. A 5.00-W resistor is connected in series with this parallel arrangement. The resistors are connected across a 1.00 ´ 102-V battery. What is the current flowing through the 20.0-W resistor?

3.15A

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?

42.5 W

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?

5.26 W, 10 A

In the circuit shown below, which bulb, when burned out, will cause all other bulbs to stop glowing?

A

Which of the following statements is true about electric forces?

Electric forces cause objects to repel or attract each other.

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?

Electrically neutral

Is it possible to have a zero electric field value between a negative and positive charge along the line joining the two charges?

No, a zero electric field cannot exist between the two charges.

Is it possible for two negative charges to attract each other?

No, they will never attract.

Is it possible to have a zero electric field value between two positive charges along the line joining the two charges?

Yes, regardless of the magnitude of the two charges.

The direction of an electric field is the direction of the force that the field would exert on

a proton

The unit of electric charge, the coulomb, is the charge on

a specific large number of electrons.

An electron and a proton

attract each other

An uncharged pith ball is suspended by a nylon fiber. When a negatively charged rubber rod is brought nearby, without touching it, the pith ball

becomes polarized.

A balloon will stick to a wooden wall if the balloon is charged

either positively or negatively.

Which of the following is not a vector?

electric charge

Every proton in the universe is surrounded by its own

electric field and gravitational field.

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:

excess electrons within the sphere move toward excess protons.

An electroscope is charged positively as shown by foil leaves that stand apart. As a negative charge is brought close to the electroscope, the leaves

fall closer together.

The electric field around an isolated electron has a certain strength 1 cm from the electron. The electric field strength 2 cm from the electron is

four times as much. half as much. the same. twice as much. None of the above choices are correct. <------

If a resistor is added to a series circuit, the equivalent resistance:

increases

At twice the distance from a point charge, the strength of the electric field

is one-fourth its original value.

The number of current paths in a series circuit is:

one

A positive ion has more

protons than electrons

Electric field lines near positive point charges

radiate outward.

A main difference between gravitational and electric forces is that electrical forces

repel or attract

Which of the following materials is the best conductor of electricity?

wet skin

When a car is struck by lightning, the resulting electric field inside the car is

zero