Help please. Physical Science!?

googol

2009-06-07 04:16:37 UTC

How does an atom become positively charged?

A. The atom gains one or more protons.

B. The atom loses one or more protons.

C. The atom gains one or more electrons.

***D. The atom loses one or more electrons.

A negative charge will attract

A. another negative charge.

***B. a positive charge.

C. a positive or negative charge.

D. a neutral charge.

The repulsion or attraction between electrically charged objects is a(n)

A. electric charge.

***B. electric force.

C. friction.

D. discharge.

What determines the strength of an electric force?

A. The size of the object in the electric field.

B. How many electrons are contained within the atom.

***C. The amount of charge that produces the field and the distance from the charge.

D. How close the object is to the charge.

When a pathway through which charges can move forms suddenly, __________ occurs.

A. friction

B. contact

***C. static discharge

D. induction

How can the electric force between two objects be reduced?

***A. Increase the distance

B. Decrease the distance

C. Increase the charge

D. Reduce friction

In which type of electric current does charge flow in only one direction?

A. Alternating current

B. Rotating current

***C. Direct current

D. Straight current

Electric current is the continuous flow of

***A. electric charge.

B. electric resistance.

C. protons and neutrons.

D. electric voltage.

Electric current flows easily through materials known as

A. electrical insulators.

***B. electrical conductors.

C. electrical resistors.

D. electrical current boosters.

In which type of current does electric charge regularly reverse its direction?

***A. Alternating current

B. Switching current

C. Reversing current

D. Direct current

Electric current does NOT flow easily through insulators. Which of the following is an example of a good electrical insulator?

A. Battery acid

B. Copper wire

C. A silver spoon

***D. Air

____________is the opposition to the flow of electric charges

***A. resistance

B. insulation

C. induction

D. voltage

What is necessary for a charge to flow?

A. The wire must have an energy source at one end.

***B. The wire must be connected in a loop that includes an energy source.

C. Potential difference of 0.

D. The wire must be connected in a loop.

According to Ohm’s law, what happens if voltage is increased?

A. The resistance is increased

B. The resistance is decreased

C. The current is increased

***D. The current is decreased

According to Ohm’s law, if voltage is maintained and resistance is increased, what happens to the current?

A. The current is not affected

B. The current doubles

C. The current is increased

***D. The current is decreased

According to Ohm’s law, a circuit’s voltage is equal to

A. current multiplied by charge.

***B. resistance multiplied by current.

C. resistance multiplied by charge.

D. induction multiplied by current.

A battery is a voltage source that converts __________ energy to __________ energy.

***A. chemical; electrical

B. electrical; chemical

C. chemical; potential

D. electrical; potential

What affects a material’s resistance, therefore changing the current?

A. Thickness, length, and composition

B. Temperature and insulation

C. Thickness, length, and temperature

D. Composition, temperature, and current

This question is a bit odd, as thickness, length, composition AND temperature can contribute to current flow. If I had to pick I would go A.

What type of circuit has two or more paths through which charges can flow?

***A. Parallel

B. Series

C. Multiple series

D. Multiple parallel

What happens if one element in a series circuit stops functioning?

A. All of the elements have limited ability to operate.

B. All of the elements in line before the non-functional one can operate.

C. All of the elements can operate.

***D. None of the elements can operate.

How does a fuse work?

A. Transfers extra charge to the earth

B. Prevents too much current from passing

*C. A wire in the center melts if too much current passes through it

D. A switch opens when current is too high

What is produced by continuously changing the voltage or current in a circuit?

A. Direct current

*B. Analog signal

C. Alternating current

D. Digital signal

Which device uses a crystalline solid to control current?

A. Vacuum tube

B. Super conductor

***C. Semiconductor

D. Solid-state component

for this question have a look here: http://en.wikipedia.org/wiki/Piezoelectricity

Vacuum tubes such as cathode-ray tubes (CRT) used in some computer monitors and televisions

A. can change alternating current into direct current.

B. can decrease the strength of an electronic signal.

C. never need to be replaced.

D. produce a digital signal of 1’s and 0’s.

This question would have to use elimination - it can't be D as it in not digital, it can't be unbreakable so it's not C, and it can technically do both A and B (oscillating voltage) so I would go for the better answer, A

?

2009-06-07 04:11:47 UTC

1.D. The atom loses one or more electrons.

2.B. a positive charge.

3.B. electric force.

4.A. The size of the object in the electric field.

5.D. induction

6.A. Increase the distance

7.C. Direct current

8.A. electric charge.

9.A. electric charge.

10.A. Alternating current

11.D. Air

12.A. resistance

13.A. The resistance is increased

14.D. The current is decreased

15.B. resistance multiplied by current.

16.A. chemical; electrical

17.C. Thickness, length, and temperature

18.D. Multiple parallel

19.D. None of the elements can operate.

20.C. A wire in the center melts if too much current passes through it

21.B. Analog signal

22.C. Semiconductor

23.D. produce a digital signal of 1’s and 0’s.

24.D. digital signal.

dun know if some of it's right or wrong...

2016-05-25 07:38:04 UTC

life science because they involve living organisms not the earth and not physics