a big chunk of my exam, anyone know anything :)​

A Big Chunk Of My Exam, Anyone Know Anything :)

Answers

Answer 1

Answer:

Explanation:

As one side of the coil moves up through the magnetic field , a current is induced in one direction. As the rotation continues and that side of the coil moves down, the induced current reverses direction. This means that the generator produces a current that is constantly changing. This is alternating current or a.c..

Answer 2

Answer is mainly 2 parts where Part 1 is basic explanation of AC generator and origin of the law of induction in AC generator where Part 2 explains the reason behind Variation of current and EMF according to the rule..:

An AC Generator "Dynamo, Alternator" generates Alternating current according to the laws of Electromagnetic Induction in a straight wire

"Wire + Magnet + Motion= Electron flow" expressed in Faraday's law and Lenz's rule "EMF= -N ΔΦ/t"

In a straight wire moving perpendicular to a magnetic field, induction of Maximum EMF occurs in the wire according to the law of induction in straight wire derived from Faraday's rule and Lenz's law "EMF= -BLV Sinθ" Where "B" is Magnetic Flux density , "L" is length of wire ,"V" is the velocity which the wire moves by and "θ" is the angle between Magnetic Field and Straight wire and as usual the - is to apply to Lenz's rule

Switching back to the Alternator which is in form of a rectangular coil "4 straight wires"

We can conclude that the induced EMF rule must be 4BLV "Ignoring Lenz's rule since it's AC" but due to the presence of 2 sides parallel to Magnetic lines at the points of axle attachment so they do not induce current Sinθ = zero

EMF= 2BLV Sinθ . Since the coil rotates around itself "Rotatory motion" Thus, Velocity must be expressed in terms of Angular velocity where V "Linear Velocity" equals Omega "ω" (which is the angular velocity) multiplied by "r" (Radius of circle of motion)

EMF= 2BL (ωxr) Sinθ  . Since the coil rotates around its own axis then diameter circle of motion equals 2r which is basically the width of the coil "W" and radius = 1/2 W

EMF= BL*W ω Sinθ.. 1/2 cancels out the 2 and we have L*W which is Area of coil

EMF= BAωN Sinθ is the final form of the rule where N is added respecting the number of turns of coil where Dynamo produces maximum EMF at angle 90°,270° between magnetic lines and normal to coil

Reason of Alternation of current in the form of a Sinusoidal wave form "where EMF starts from zero rises to maximum emf descends to zero then descends again to -maximum emf then back to zero" is due to the coil's rotatory motion and changing of angle between magnetic field and normal to coil according to the above rule , For example Coil starts motion from zero position where the coil itself is Normal to magnetic field but the normal to coil is Parallel to the field so θ = zero thus no emf induced

After start of motion and rotation of coil using handle the angles start to change from 0° till 90° "1/4 cycle" Induced EMF increases from zero according to rule till reach maximum at 90° where Sin90 equals 1 , When continuing motion and according to sin graph value of EMF decrease as we proceed from angle 90° till 180° "another 1/4 cycle summing up to 1/2 cycle" where EMF reaches zero again at 180° since Sin180 equals 0, As we the rotation proceeds from angle 180° till 270° "another 1/4 cycle summing up to 3/4 cycle" EMF Increases till reaching Maximum BUT in opposite direction of motion since basically the - sign is a symbol of direction in physics but since the Graph is mathematical it is expressed as a decrease in EMF till reach -Max since Sin270 equals -1 which is opposite to max, Finally at the last quarter cycle from angle 270° till 360° EMF starts to decrease back to zero Physically but Mathematically seen as an increase since we were at -Max

So to sum it all up...AC current is due to Variation of Angle between Motion of coil and Magnetic lines causing the Variation of Current in tiny amounts of time with very high frequency

A Big Chunk Of My Exam, Anyone Know Anything :)

Related Questions

In an electrical circuit, what happens to the current flowing through the wire if the initial voltage of 18 V is doubled, and the initial resistance of 35 Ohms is reduced by a factor of 4?

ANSWER QUICKLY PLEASE! ITS URGENT!

Answers

The current is increased by a factor of 8.

From 18/35 A. to 144/35 A.

The electric current changes from 0.514 ampere to 4.14 ampere, i.e, electric current flow in the circuit increases 8 times.

What is electric current?

A stream of charged particles, such as electrons or ions, travelling through an electrical conductor or a vacuum is known as an electric current. The net rate of electric charge flowing through a surface or into a control volume is how it is calculated.

Initial electric current flowing through the circuit = (18 volt ÷ 35 ohms)

= 0.514 ampere.

When the initial voltage of 18 V is doubled, and the initial resistance of 35 Ohms is reduced by a factor of 4, electric current flowing through the circuit will be = (2 × 18 volt )÷ (35 ohms÷4)

= 4.114 ampere.

Hence, electric current changes from 0.514 ampere to 4.14 ampere, i.e., electric current flow in the circuit increases 8 times.

Learn more about electric current here:

https://brainly.com/question/2264542

#SPJ2

A given wire of resistance 1 ohm
is stretched to double
its length. What will be its new resistance ?​

Answers

Ok so i rlly dont know dis one srry

the object having uniform velocity has zero acceleration why​

Answers

Because that's what "uniform velocity" means.

Uniform velocity means constant speed in a straight line.

Acceleration means changing speed OR changing direction.

what is a underwater mountain that rises above sea level called

Answers

Answer:

Undersea mountain ranges are mountain ranges that are mostly or entirely underwater, and specifically under the surface of an ocean. If originated from current tectonic forces, they are often referred to as a mid-ocean ridge. In contrast, if formed by past above-water volcanism, they are known as a seamount chain.

Explanation:

what do you mean by efficiency of a machine?​

Answers

Answer:

Efficiency in general means How well an object does with respect to its designated purpose for example a battery with Voltage of 10 volts won't exert 10 volts but slightly less due to internal resistance let's say 8V so efficiency will be 8/10 x100 = 80%

Same thing with a machine/engine If an engine is designed to produce 150 horsepower it won't give you the full energy due to part of the energy being dissipated in form of heat due to friction so let's say 145 hp is produced which is 96% efficiency

True or False: A lake has less thermal energy than a glass of water, because it is larger.

Answers

False is urrr answer

An electron with a charge value of 1.6 x 10-19 C is moving in the presence of an electric field of 400 N/C. What force does the electron experience?

Answers

Answer:

4.0×10⁻¹⁷ N

Explanation:

any help would be appreciated! :)​

Answers

Answer:

primary voltage/secondary voltage = number of turns on primary coil/number of turns on secondary coil

V1/V2= N1/N2

1.5/5 = 150/N2

0.3 = 150/N2

N2= 150/0.3

N2 = 500

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This graph indicates that the acceleration between 2.00 and 4.00 seconds is the same as that between 12.00 and 14.00 seconds.

True
False

Answers

I believe it’s false I’m probably wrong I ju at need points for my test

An object that can push
or pull on iron without
touching it is called a:

Answers

Answer:

A magnet

Explanation:

is an object that can attract some metals like iron

pls help


Can humans start to direct their own evolution and take over natural selection? Are we influencing our own evolution?

Answers

Answer:

yes they can

Explanation:

sure if they want

A thin beam of light of wavelength 50 μm (in the infrared portion of the em spectrum) goes through

a thin slit and falls on a screen 3.00 m past the slit. You observe that the first completely dark fringes

occur on the screen at distances of ±8.24 mm from the central bright fringe, and that the central bright

fringe has an intensity of I0 at its center. (a) How wide is the slit? (b) What is the highest order fringe

this scenario is capable of producing? (c) What is the intensity of light at a point on the screen that is

one-quarter of the way from the central bright fringe to the first dark fringe?

Answers

Solution :

Given :

Wavelength of the thin beam of light, λ = 50 μm

Distance of the screen from the slit, D = 3.00 m

Width of the fringe, Δy = ±8.24 mm

Therefore, width of the slit is given by :

[tex]$d=\frac{n \lambda D}{\Delta y}$[/tex]

  [tex]$=\frac{2 \times 50 \times 10^{-9} \times 3}{2 \times 8.24 \times 10^{-3}}$[/tex]

  = 0.000018203 m

  = 0.0182 mm

  = 0.018 mm

The intensity of light is given by :

[tex]$I=I_0\left(\frac{\sin \beta /2}{\beta/ 2}\right)^2$[/tex]   , where [tex]$\beta=\frac{2 \pi D \sin \theta}{\lambda}$[/tex]

[tex]$I=I_0\left(\frac{\sin \frac{\pi d \sin \theta}{\lambda}}{\frac{\pi d \sin \theta}{\lambda}}\right)^2$[/tex]

[tex]$I=I_0\left(\frac{\sin \frac{\pi d y}{D\lambda}}{\frac{\pi d y}{D\lambda}}\right)^2$[/tex]

Now, [tex]$\frac{dy}{D \lambda} = \frac{8.24 \times 10^{-3}\times 0.018 \times 10^{-3}}{4 \times 50\times 10^{-9}\times 4}$[/tex]

               = 0.1854

               ≈ 0.18

[tex]$I=I_0\left(\frac{\sin 0.56}{0.56}\right)^2$[/tex]

  [tex]$=I_0 \times 0.81$[/tex]

  = 2  x0.81

  [tex]$= 1.62 \ W/m^2$[/tex]

 

The infrasound waves were at just the right ________________ to vibrate the human eye. no frikin links!!!

Answers

Answer:

pitch

Explanation:

Which of the following diagrams involves a virtual image?
A. A convex lens is shown centered at 7 on a ruler that goes from 0 to 14 centimeters. The object is located at 5, and the focal points are at 5.5 and 8.5. The three light rays are shown to form the image located at 13.
B. A convex lens is shown centered at 7 on a ruler that goes from 0 to 14 centimeters. The object is located at 4, and the focal points are at 5.5 and 8.5. The three light rays are shown to form the image located at 10.
C. A convex lens is shown centered at 7 on a ruler that goes from 0 to 14 centimeters. The object is located at 6, and the focal points are at 5.5 and 8.5. The three light rays are shown to form the image located at 4.

Answers

I think the answer is c because the image is shown on the same side as the object

The Diagram that involves a virtual image is the third diagram  ( C )

The third diagram involves a virtual image because it has its Image on the same side as the object as seen from the description :

The convex lens is centered at 7cm and the object is located at 6cm while the Focal points are 5.5 and 8.5 cm  

and the Image is formed at 4 cm ( on the same side/ half  of the Ruler ).

For a real image to be formed the Image will appear behind the position of the convex lens as seen in the diagram attached below and in Diagrams A and B .

Hence Diagram C shows that the Image is a virtual image

Learn more of convex lens : https://brainly.com/question/12323990

The spring to launch a pinball in a pinball machine is compressed 25 cm and has a spring constant of 140 N/m.
a. How much energy is stored in the spring when it is fully compressed?

b. If friction removes 3.75 J of energy while the spring launches, how much energy will the pin ball end up having?

Answers

Answer:

I think it is 5.6. This is my answer

solute + solvent = ??

Answers

solute + solvent = a solution

I found a really good image for this situation:

pls answer this right I will give you a brainiest.

Answers

Answer:

i would pick c

Explanation:

because, w and y it is very bright and bright can be very conductive like it said.

A student does an experiment with a string vibrating at 20 hertz and observes the resonance pattern shown in the
diagram:
What is the speed of the wave on the string in Figure 24-3A?
4.0 m/s
8.0 m/s
20 m/s
100 m/s

Answers

Answer:

v = 8.0 m/s

Explanation:

The diagram clearly shows that the string is vibrating in the 5th harmonic. Hence, the length of string in terms o wavelength can be given as:

[tex]L = \frac{5}{2}\lambda\\\\\lambda = \frac{2}{5} L[/tex]

where,

λ = wavelength = ?

L = Length of string = 1 m

Therefore,

[tex]\lambda = \frac{2}{5}(1\ m)\\\\\lambda = 0.4\ m[/tex]

Now, the speed of the wave can be given by the following formula:

[tex]v = f\lambda\\[/tex]

where,

v = speed of wave =?

f = frequency of wave = 20 Hz

Therefore,

[tex]v = (20\ Hz)(0.4\ m)\\v = 8\ m/s\\[/tex]

Hence, the correct answer is:

v = 8.0 m/s

in comparing sunspots to other areas of the sun's surface one can say that sunspots are...?
slower in reacting to creating energy
similar in temp
cooler
warmer​

Answers

Answer:

D. Cooler

Explanation:

The Sun's surface has a temperature ranging from 6 000 Kelvin, thus it is very hot. The radioactive reaction in the core of the Sun is a nuclear fusion reaction. This reaction ensures continuous release of high energy from the surface of the Sun.

But during the reaction, some parts becomes cooler than other parts on its surface. Which is due to the release of high amount of energy into space. The Sun's spot can be found in the cooler part of the Sun.

Answer:

C. Cooler

Explanation:

Photos A and B both show the same field of view containing a star-forming molecular cloud. One of the photos was taken in visible light and the other in infrared light. Which one is the visible-light photo, and how do you know?

Answers

Hello. You did not present the photos to which the question refers, which makes it impossible for your question to be answered. However, I will try to help you in the best possible way.

Your question informs us that the photos are of a star-forming molecular cloud. The molecular cloud has dust, especially when the star is forming. In this case, we must keep in mind that in photos taken in visible light, the dust is able to appear, especially in space, where this dust would not reflect light, unlike the star in formation. In this case, we can conclude that in the case of the photo taken in visible light, we could see the molecular cloud as a dark spot, due to the dust. However, it would not be possible to view it in a photo taken with infrared light.

An equipoterntial surface that surrounds a + 3.0 pC point charge has a radius of 2.0 cm. What is the potential of this surface?​

Answers

Answer:

Electric potential = 0.00054 V

Explanation:

We are given;

Charge; q = 3 pC = 3 × 10^(-12) C

Radius; r = 2 cm = 0.02 m

Formula for the electric potential of this surface will be;

V = kqr

Where;

K is a constant = 9 × 10^(9) N⋅m²/C².

Thus;

V = 9 × 10^(9) × 3 × 10^(-12) × 0.02

V = 0.00054 V

A drop of oil of volume 2×10-¹²m³ spreads out on water to make a circular film of diameter 10-³m . find the thickness of the film​

Answers

Answer:

Explanation:

2×10-¹² = (5-³*5-³* 3.14)*h

h=0.00000001 m

What is assimilation? Discuss the importance of social assimilation. Discuss immigration and some key challenges that an immigrant might face. What could be some benchmarks through which you can measure immigrant assimilation? What are some challenges that partners in an intercultural marriage may face? What can they do to avoid conflicts and resolve an argument or a disagreement?

Answers

Answer:

Assimilation refers to the process by which a person or ethnic group that constitutes a minority people imitates the culture of the majority population and, when the process is complete, completely abandons its own culture. Thus, the original cultural differences disappear and society becomes a monoculture. For example, immigrant groups or colonized indigenous peoples may abandon their culture, either spontaneously or after religious persecution and coercive measures, called assimilation policies.

A number of immigrant groups were assimilated into American society during the 19th century in what is usually described as a cultural melting pot or Americanization. In this case, the adaptation was not one-way, and largely spontaneous.



A 2000 kg boat drifts along the waves at a velocity of 3 m/s. What is

the kinetic energy of the boat?

Select one:

18,000 J

6000 J

оооо

OJ

9000 J

Answers

Answer:

K = 9000 J

Explanation:

Given that,

The mass of a boat, m = 2000 kg

The velocity of the boat, v = 3 m/s

We need to find the kinetic energy of the boat. We know that the kinetic energy of an object is given by :

[tex]K=\dfrac{1}{2}mv^2\\\\K=\dfrac{1}{2}\times 2000\times 3^2\\\\K=9000\ J[/tex]

So, the required kinetic energy is equal to 9000 J.

HELP MEEEE NO LINKS
Resonance occurs in the middle ear.


Please select the best answer from the choices provided

T
F

Answers

Answer:

The answer would be TRUE

Explanation:

The mean resonance frequency of the human middle ear under air conduction (AC) excitation is known to be around 0.8-1.2 kHz. However, studies suggest that the mean resonance frequency under bone conduction (BC) excitation is at a higher frequency around 1.5-2 kHz.

can i plz have brainliest???

Answer:

T

Explanation:

its true

PLSS HELP YEA 25 POINTSSSS

CAN HUMANS BE " DE-EVOLVING" EXPLAIN WHY OR WHY NOT

Answers

No we are not developing because we haven’t showed old evolution traits past humans had

Answer: There is no such thing as devolution from a biological standpoint. The idea that humans might regress or "develop" assumes that there is a preferred hierarchy of structure and function, such as lungs being preferable to breathing with gills.

Please help will mark brainliest
Why is the melting of ice a physical change?
A.
It changes the chemical composition of water.
B.
It does not change the chemical composition of water.
C.
It creates new chemical bonds.
D.
It forms new products.
E.
It is an irreversible change that forms new products.

Answers

Answer:

b

Explanation:

it melts yes but it's still water [same element] so there fore it's a physical change

Answer:

It does not change the chemical composition of water. Explanation: A physical reaction is defined as the reaction in which a change in shape, size takes place. No new substance gets formed in these reactions.

Explanation:

Hope this helped

Which of the following is an example of potential energy?
A. The plant sitting on the desk
B. The airplane Flying in the air
C. The car driving on the Street
D. The person standing up

Answers

Answer:

A

Explanation:

potential energy is energy due to position

What is an element?
give ur own response

Answers

[tex]\huge{\textbf{\textsf{{\color{pink}{An}}{\blue{sw}}{\pink{er}} {\color{blue}{:}}}}}[/tex]

Elements are one type of atom.

Elements are complete chemical substances which relate to a single entry in the modern periodic table. Elements consist of one kind of atoms only.

Thanks Hope it helps

Can someone please help me with this

Answers

Answer:

B because the earth rotational axis tilt away from the sun.

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