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yKpoI14uk [10]
3 years ago
6

Can anyone tell me which ones of these are true and which ones are false pls

Physics
2 answers:
nexus9112 [7]3 years ago
6 0

Answer: *use image inserted*

Explanation:

USA test prep.

Akimi4 [234]3 years ago
4 0

There are two important facts to recall that will help answer this question:

1. The resistance of a segment of conducting wire is given by this equation:

R = ρL/A

ρ is the resistivity of the material making up the wire. This value is a constant that depends on the properties of the material. Resistivities for various materials can be found with a quick Google search.

L is the length of the wire.

A is the cross-sectional area of the wire.

From this equation you can tell that a wire's resistance will increase if it is made longer and/or thinner, and the resistance will decrease if it is made shorter and/or thicker. Mathematically speaking, the resistance is directly proportional to the length and inversely proportional to the cross-sectional area.

2. The other fact is that a conductor's resistance is also dependent on its temperature. Generally, as a conductor gets hotter, its resistance increases.


Let us now tackle the list of statements:

1. A shorter wire will allow electricity to move through at a higher rate than a longer wire.

According to the equation for a conductor's resistance, a shorter wire will have a smaller resistance.

Now recall that current is the movement of electric charges and Ohm's law:

V = IR

V is the applied potential difference between the ends of the wire.

I is the current.

R is the resistance.

Assuming you keep the potential difference constant, when you have a smaller resistance, you will have a larger current.

Statement 1 is correct.


2. A short, thick, cold wire is the best conductor.

According to the equation for a conductor's resistance, a shorter, thicker wire will have lesser resistance. A cold temperature will also help to keep the resistance low. A low resistance means a higher current.

Statement 2 is correct.


3. How well a material conducts current is an internal factor affecting resistance.

Statement 3 is correct, assuming the physical property in question is the material's resistivity. The resistivity is one of the factors in the equation for a conductor's resistance.

4. If you double the length of a wire, you cut the resistance in half.

According to the equation for a conductor's resistance, increasing the length of a wire increases the resistance. Statement 4 is false.


5. If you double the thickness of a wire, you cut the resistance in half.

According to the equation for a conductor's resistance, increasing the thickness of a wire decreases its resistance. Statement 5 is true.


6. Superconductors have no measurable resistance.

A superconductor by definition is able to conductor electric current with virtually no resistance. Statement 6 is true.


7. The higher the temperature of the conductor, the lower the resistance.

A conductor's resistance generally increases with temperature. Statement 7 is false.


8. The resistance in a wire with less thickness is less.

According to the equation for a conductor's resistance, making a wire thinner will increase its resistance. Statement 8 is false.


9. Thickness, length, and temperature are internal factors that affect resistance.

Thickness (cross-sectional area) and length are both factors in the equation determining a conductor's resistance. Temperature is also known as a factor that affects resistance. Statement 9 is true.


10. When a light is first switched on, the light bulb's filament has a lower resistance than after it gives off light for awhile.

A device that draws a current will generally heat up given sufficient time. This increases the device's resistance. Statement 10 is correct.

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Which of the following statements about the resistsance of a wire is correct? Select THREE answers.
viva [34]

Answer:

Its a

Explanation:

4 0
3 years ago
A pendulum bob executing simple harmonic motion has 2cm and 12Hz as amplitude and frequency respectively. Calculate the period o
Jobisdone [24]

Answer:

Explanation:

The amplitude is extraneous information for this question.

Period (T) is simply a measure of time (how long it takes to complete a full cycle).

The frequency (f), is the reciprocal (how many cycles it can complete per unit of time).

The frequency reported is 12Hz.  Hz is a unit meaning "cycles per second"

Thus 12cycles = 1second.

To find the number of seconds per cycle, simply create the other unit fraction and simplify:

T=\frac{1second}{12cycles}\\T=0.8\bar{3}\frac{seconds}{cycle}\\

T=0.83seconds

7 0
2 years ago
A charge q = 3 × 10-6 C of mass m = 2 × 10-6 kg, and speed v = 5 × 106 m/s enters a uniform magnetic field. The mass experiences
NeX [460]

Answer:

Magnetic field, B = 0.004 mT

Explanation:

It is given that,

Charge, q=3\times 10^{-6}\ C

Mass of charge particle, m=2\times 10^{-6}\ C

Speed, v=5\times 10^{6}\ m/s

Acceleration, a=3\times 10^{4}\ m/s^2

We need to find the minimum magnetic field that would produce such an acceleration. So,

ma=qvB\ sin\theta

For minimum magnetic field,

ma=qvB

B=\dfrac{ma}{qv}

B=\dfrac{2\times 10^{-6}\ C\times 3\times 10^{4}\ m/s^2}{3\times 10^{-6}\ C\times 5\times 10^{6}\ m/s}

B = 0.004 T

or

B = 4 mT

So, the magnetic field produce such an acceleration at 4 mT. Hence, this is the required solution.

4 0
3 years ago
An 800-g block of ice at 0.00°C is resting in a large bath of water at 0.00°C insulated from the environment. After an entropy c
Allisa [31]

Answer:

Unmeltedd ice = 308.109 g

Explanation:

Gibbs Free energy:

A systems Gibbs Free Energy is defined as the free energy of the product of the absolute temperature and the entropy change less than the enthalpy change.

Therefore, G = ΔH-TΔS

where G is Gibbs Free Energy

          ΔH is enthalpy change

          T is absolute temperature

          ΔS is entropy change

Here since there is a phase change, therefore G will be 0.

∴ΔH = TΔS

Given: Temperature, T = 0°C = 273 K

           Entropy change,ΔS = 600 J/K

           Latent heat of fusion of water = 333 J/g

∴ΔH = TΔS

  ∴ΔH = 273 x 600

           = 163800 J

So this is the amount of enthalpy that will be used into melting of ice.

  ∴ΔH = mass of ice melted x latent heat of fusion of water

    Mass of ice melted = ΔH / latent heat of fusion of water

                                     = 163800 / 333

                                     = 491.891 g

This is the mass of ice melted.

And initial amount of ice is 800 g

Amount of ice left after melting = Initial amount of ice - amount of ice melted

                                                   = 800-491.891

                                                  = 308.109 g

Amount of ice remained after melting = 308.109 g

8 0
3 years ago
Will mark Brainliest!
DENIUS [597]
I think it’s A protons .. hope this helps
8 0
3 years ago
Read 2 more answers
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