why are circuit breakers used in parts of national grid ?

Answers

Answer 1

Answer:

To protect control circuits or small devices with insufficient cutting power

Explanation:


Related Questions

Three circuits diagrams are shown. Which statement about the circuit diagram is accurate?

Answers

Answer:

Circuits A and B are both series circuit.

Explanation:

In series combination, two resistors are connected with their ends to ends. The equivalent resistance in this case is given by :

[tex]R_s=R_1+R_2+...[/tex]

In circuit A both voltage (V) and R₁ are connected in series.

Similarly in circuit B, voltage (V), R₁ and R₂ are in series./

Hence, the correct option is (a).

A 1-m3 tank holds a two-phase liquid-vapor mixture of carbon dioxide at – 17 °C. The quality of the mixture is 70%. For saturated carbon dioxide at – 17 °C, vf = 0.9827×10-3 m3/kg and vg =1.756×10-2 m3/kg. Determine the masses of saturated liquid and saturated vapor, each in kg. What is the percent of the total volume occupied by saturated liquid?

Answers

Answer:

a)  [tex]m_v= 56.16 Kg[/tex]

    [tex]m_l= 14.04 Kg[/tex]

b)  [tex]\mu=1.37\%[/tex]

Explanation:

From the question we are told that:

Volume of tank [tex]V_t=1m^3[/tex]

Temperature of [tex]CO_2=-17^oC[/tex]

Quality of the mixture [tex]Q= 70%[/tex]

Specific Volume constants at [tex]-17^oC:[/tex]

 [tex]v_f = 0.9827*10^{-3} m3/kg[/tex]

 [tex]v_g =1.756*10^{-2} m3/kg.[/tex]

Generally the equation for Specific Volume is mathematically given by

 [tex]v = v_f + x (v_g -v_f)[/tex]

 [tex]v= (0.9827 * 10^{-3} ) + 0.8 * (17.56 * 10^{-3} -0.9827 * 10^{-3})[/tex]

 [tex]v= 0.014244 m3/Kg[/tex]

Generally the equation for Mass is mathematically given by

 [tex]m=\frac{v'}{v}[/tex]

 [tex]m=\frac{1}{0.014244}[/tex]

 [tex]m=70.20 Kg[/tex]

Generally the Mass of saturated Vapor is mathematically given by

 [tex]m_v=0.8 * (70.202)[/tex]

 [tex]m_v= 56.16 Kg[/tex]

Generally the Mass of saturated Liquid is mathematically given by

 [tex]m_l = (70.20 Kg)-(56.16 Kg)[/tex]

 [tex]m_l= 14.04 Kg[/tex]

b)

Generally the equation for Volume is mathematically given by

 [tex]v_l = m_l x v_f[/tex]

 [tex]v_l= (14.04 Kg) (0.9827 x 10{-3} m3/kg)[/tex]

 [tex]v_l= 0.01379 m^3[/tex]

Therefore Percentage of liquid

 [tex]\mu = \frac{v_l}{v} * 100 \%[/tex]

 [tex]\mu= [(0.01379 m^3)/(1 m^3)] *100 \%[/tex]

 [tex]\mu=1.37\%[/tex]

Please help me find the answers!

Answers

Answer:

1. T₁ is approximately 100.33 N

T₂ is approximately -51.674 N

2. 230°F is 383.15 K

3. Part A

The total torque on the bolt is -4.2 N·m

Part B

Negative anticlockwise

Explanation:

1. The given horizontal force = 86 N

The direction of the given 86 N force = To the left (negative) and along the x-axis

(The magnitude and direction of the 86 N force = -86·i)

The state of the system of forces = In equilibrium

The angle of elevation of the direction of the force T₁ = 31° above the x-axis

The direction of the force T₂ = Downwards, along the y-axis (Perpendicular to the x-axis)

Given that the system is in equilibrium, we have;

At equilibrium, the sum of the horizontal forces = 0

Therefore;

T₁ × cos(31°) - 86 = 0

T₁ = 86/(cos(31°)) ≈ 100.33

T₁ ≈ 100.33 N

Similarly, at equilibrium, the sum of the vertical forces = 0

∴ T₁×sin(31°) + T₂ = 0

Which gives;

100.33 × sin(31°) + T₂ = 0

T₂ = -100.33 × sin(31°) ≈ -51.674

T₂ ≈-51.674 N

2. 230° F to Kelvin

To convert degrees Fahrenheit (°F) to K, we use;

[tex]Degrees \ in \ Kelvin, K = (x^{\circ} F + 459.67) \times \dfrac{5}{9}[/tex]

Pluggining in the given temperature value gives;

[tex]Degrees \ in \ Kelvin, K = (230^{\circ} F + 459.67) \times \dfrac{5}{9} = 383.15[/tex]

230°F = 383.15 K

3. Part A

Torque = Force × perpendicular distance from the line of action of the force

Therefore, the clockwise torque = 9 N × 0.4 m = 3.6 N·m (clocwise)

The anticlockeisre torque = 13 N × 0.6 m = 7.8 N·m (anticlockwise)

The total torque o the bolt = 3.6 N·m - 7.8 N·m = -4.2 N·m (clockwise) = 4.2 N·m anticlockwise

Part B

The torque is negative anticlockwise.

The force of friction acting on a sliding crate is 223 N.
How much force must be applied to main- tain a constant velocity?

Answers

Answer:

Friction Opposes Motion of an Object.

Now

To get the Net force that Moves an Object and causes acceleration....You subtract the Frictional force

Net force = Pushing Force - Frictional Force

Recall

Net Force; F=Ma

Ma = P - Fr

Now the question asked for How Much force Must be applied to Maintain a Constant velocity.

In a Constant Velocity Motion... Acceleration do not change... Its Zero

So Putting this into the formula above

M(0) = P - Fr

0=P - Fr

Fr = P.

This means

That The force needed to keep this object Moving at Constant Velocity Must be equal to its Frictional Force

Since Frictional Force; Fr =223N

The Applied Force(Pushing Force) Must be equal to 223N too.

What is the gravitational force between two objects?​

Answers

Answer:

Gravitational force -an attractive force that exists between all objects with mass; an object with mass attracts another object with mass; the magnitude of the force is directly proportional to the masses of the two objects and inversely proportional to the square of the distance between the two objects.

Explanation:

hope it helped

Gravitational force

A series circuit is shown in the diagram below. What is the potential drop
across Rg? (Ry - 200, R2-40 Q, R3-60 , V = 60 V) (Ohrris law: V-IR)

Answers

Answer:

Option C. 20 V

Explanation:

We'll begin by calculating the equivalent resistance of the circuit. This can be obtained as follow:

Resistor 1 (R₁) = 20 Ω

Resistor 2 (R₂) = 40 Ω

Resistor 3 (R₃) = 60 Ω

Equivalent Resistance (R) =?

R = R₁ + R₂ + R₃ (series arrangement)

R = 20 + 40 + 60

R = 120 Ω

Next, we shall determine the current in the circuit. This can be obtained as follow:

Voltage (V) = 60 V

Equivalent Resistance (R) = 120 Ω

Current (I) =?

V = IR

60 = I × 120

Divide both side by 120

I = 60 / 120

I = 0.5 A

Finally, we shall determine the potential drop across R₂. This can be obtained as follow:

Current (I) = 0.5 A

Resistor 2 (R₂) = 40 Ω

Voltage (V) =?

V = IR₂

V = 0.5 × 40

V = 20 V

Therefore, the potential drop across R₂ is 20 V

List two applications of an echo? ​

Answers

Answer:

I think the echo sounds do not depend on the direction of the sound and sound the same as the original sound

Explanation:

An echo is defined as a sound that is produced when a sound wave is reflected back from any hard surface and repeated.

Two major application of echo include:

- Bats, fisherman, and dolphins use echoes to detect or identify any object /obstruction.

- Echo is widely used in medical science applications for imaging of human organs such as echocardiography and ultrasound.

I hope this help you!:)

Ball X has a mass of 8kg and is moving toward ball Y (which is sitting still) at 2m/s. After they collide, ball X is
sitting still. How fast is ball Y moving after the collision if it has a mass of 4kg?

Answers

Answer:

v = 4 m/s

Explanation:

Given :

Ball X :

Mass, m1 = 8kg ;

Initial Velocity, u1 = 2 m/s

Final velocity, v1 = 0

Ball Y:

Mass, m2 = 4kg ;

Initial Velocity, u2 = 0 m/s

Final velocity, v2 = v

(m1u1 + m2u2) = (m2v2 + m1v1)

(8*2 + 4*0) = (4*v + 4*0)

16 + 0 = 4v + 0

16 = 4v

v = 16 / 4

v = 4 m/s

Answer:

Explanation:

This is the Law of Momentum Conservation which for us looks like this:

[tex][m_xv_x+m_yv_y]_b=[m_xv_x+m_yv_y]_a[/tex] and that should look familiar to you if this is what you are doing in physics. Filling in our particular info:

[(8.0 × 2.0)+ (4.0 × 0.0)] = [(8.0 × 0.0) + (4.0v)] and

16 + 0 = 0 + 4.0v and

16 = 4.0v so

v = 4.0 in the direction of ball X

As a sample's temperature increases, which two factors also increase?
A. Particle size
B. Particle boiling point
DC. Particle kinetic energy
D. Particle speed​

Answers

particle kinetic energy and particle speed

The spring in the toy is compressed 0.070 meter by using a downward force of 12.0 newtons. Calculate the spring constant, in N/m, of the spring.

Answers

Answer:

The spring constant is 171.43 N/m.

Explanation:

compression in spring, x = 0.07 m

force, F = 12 N

Let the spring constant is K.

Use the formula of the restoring force of the spring

F = K x

12 = K (0.07)

K = 171.43 N/m  

A box at rest is in a state of equilibrium half way up on a ramp. The ramp has an incline of 42° . What is the force of static friction acting on the box if box has a gravitational force of 112.1 N ?

70 N
80 N
75 N
85 N

Answers

Answer:

the correct answer  is 75 N

Explanation:

This is a translational balancing exercise, let's set a reference system with the x-axis in the direction of the plane and the y-axis perpendicular to the plane.

In this reference system the force to decompose is the weight

         sin 42 = Wₓ / W

        cos 42 = W_y / W

        Wₓ = W sin 42

        W_y = W cos 42

        Wₓ = 112.1 sin 42 = 75.0 N

        W_y = 112.1 cos 42 = 83.3 N

The expression for equilibrium on the x-axis is

         Wₓ - fr = 0

         fr = Wₓ

         fr = 75.0 N

the correct answer  is 75 N

Give atleast (5) etypes of cleaning tools , equipment,supplies, and materials that you can find either in your home or school. Identify each use

Answers

Answer and Explanation:

Cleaning tools, equipment, supplies, and materials that can be easily found in a school in one each are: scrub brush, sponges, buckets and brooms.

These equipments are essential to promote a clean, organized and safe environment and for this reason, they can be easily found both at school and in a home, since the cleanliness of these two places is essential for the well-being, proactivity and health of the people who attend them.

Atividade 1) A presença do campo magnético terrestre proporciona alguns efeitos interessantes. Dentre eles estão as auroras polares. Faça uma pesquisa e explique como esse fenômeno ocorre. Atividade 2 Utilizando a simulação mostrada na figura abaixo, aproxime o ímã da bússola em várias posições ao longo do plano. a) O que representam as pequenas agulhas ao redor do ímã? b) O que acontece com a agulha da bússola quando o ímã é movimentado ao seu redor? c) Marque a seleção "Mostrar medidor de campo". Movimente o medidor de campo O que você observa em relação ao campo magnético⃗ , quando o medidor de campo se aproxima do imã? c) Marque a caixa de seleção "planeta Terra". Como são mostradas as polaridades do ímã? Por que aparece dessa forma?

Answers

The answer is 1 the first one is the only one that makes sense

What is meant by the statement that a laser beam is coherent, mono-chromatic and parallel?

Answers

Answer:

Laser light however contains only one wavelength. This property makes lasers monochromatic, meaning of one color. Another property of lasers is that all the wavelengths are in phase, meaning they wave together. This property is called coherency. Laser light travels in the same direction, parallel to one another.

Explain hydraulic machine as force multiplier.

Answers

Answer:

The pressure on piston 1 is always equal to the pressure on piston 2. ... It is equal to the force on piston 1, multiplied by A2/A1. Hydraulic systems are called force multipliers for exactly this reason. A small force can be increased by using hydraulics

Explanation:

Radhe Radhe

What type of solution is seltzer water?

Answers

Answer: Gas-liquid

Explanation:

Seltzer water is also called “sparkling water” or “carbonated water,” and it refers to the water which has been infused with carbon dioxide gas, which then causes it to bubble.

The type of solution that seltzer water is "gas liquid". Here, the solution is liquid while the solute is gas.

Answer:

gas - liquid

Explanation:

i took the quiz

15. You are watching a baseball game on television that 15

being broadcast from 4500 km away. The batter hits

the ball with a loud "crack" of the bat. A microphone

is located 22 m from the batter, and you are 2.0 m from

the television set. On a day when sound travels 343 m/s

in air, what is the minimum time it takes for you to hear

the crack of the bat after the batter hits the ball?

Answers

Answer:

t_total = 6.99 s

Explanation:

It asks us how long it takes to hear the sound, for this we must look for the time (t₁) it takes for the sound to reach the microphone, the time it takes for the video signal (t₂) to reach the television and the time (₃) it takes for the TV sound to reach us, so the total delay time is

         t_total = t₁ + t₂ + t₂

we look for t1, it indicates that the distance x = 22m

          v = x / t

           t = x / v

           t₁ = 22/343

           t₁ = 6.41 10-2 s

time t₂

          t₂ = 4500 103/3 108

          t₂ = 1.5 10-5 s

time t₃

          t₃ = 2/343

          t₃ = 5.83 10⁻³

Total time is

         t_total = t₁ + t₂ + t₃

         t_total = 6.41 10⁻² + ​​1.5 10⁻⁵ + 0.583 10⁻²

         t_total = 6.99 s

Explain the effect of the multiplier in the conversion of a moving coil galvanometer to a voltmeter.

Answers

Answer:

Explanation:

A galvanometer which is used for the measurement of a very small current can be converted to a voltmeter when it is connected to a high resistance or a multiplier is a series. The purpose of this is to reduce the amount of current that goes through the galvanometer so as prevent full scale deflection.

the same crops are grown in different seasons true or false​

Answers

Answer: False

Explanation:

Growing different crops in different seasons in the same field will deplete the soil of nutrients. False. Growing different crops In the same field actually help to improve the fertility of the field.

what is the difference between static electricity produced by friction, conduction of electricity, and induction of an electrical charge?

Answers

Answer:

ummm a whole bunch

Explanation:

Temperature of substance changes from -20 celsius to 20 celsius. What is temperature change in kelvin scale

Answers

Answer:

313kelvin

Explanation:

40 degree celcius plus 273=313K

A young student drops a stone off the side of a cliff that is 41 meters high. How long does it take the stone to hit the ground below?


A)
2.89 s

B)
8.36 s

C)
3.20 s

D)
2.04 s

Answers

Im sure it’s B
Explanation: because 41 meters in feet is 134 feet 6.173 inches and every 33.5 feet should be dropping by 2.09 seconds so it should be 8.36

2.09 x 4= “8.36”
YOUR WELCOME<3

The objective of baseball is to OUTSCORE your opponent.
True or false
Help ?

Answers

Answer:

True

Explanation:

The team with the most points at the end of the game is the winner.

Yes it is true - hope it help

how do you do question 1?

Answers

Answer:

DONT KNOW SORRY XD

Explanation:

BEC I AM BRAINLESS USING BRAINLY

Answer:

Ok, so at point 20 on the x axis you put 12 on the y-axis, then draw a line from 0, 0 to that point, this demonstrates the acceleration to 12 m/s.

Next, calculate the time he cycled for if he suckled the distance of 4800m :

4800/12 = 400 s

Put a dot at 400, 12. The time changed but the speed remained constant, line is horizontal.

For the last one, he had to decelerate at an equal speed. Since there is 100 s left of the journey at that stage, You need to draw a straight line from the previous point to 500, 0. So at time 500 he was not accelerating at all, he came to rest.

a) ?

b) -0.16 meters a second acceleration

with respect to air the refractive index of ice is 1.31 and that of rock salt is 1.54 calculate the refractive index of rock salt with respect to ice​

Answers

Answer:

1.17

Explanation:

Given that,

The refractive index of ice wrt air = 1.31

The refractive index of rock salt wrt air = 1.54

We need to find the refractive index of rock salt with respect to ice.

We know that,

refractive index = (speed of light in air or vaccum)/( speed of light in that medium)

So,

The speed of light in ice = c/(1.31)

The speed of light in rock salt = c/(1.54)

So, the refractive index of rock salt with respect to ice​ is :

[tex]\mu=\dfrac{1.54}{1.31}\\\\=1.17[/tex]

So, the required refractive index of rock salt wrt ice is 1.17.

What is a temperature of 40 K equivalent to in degrees Celsius?

Answers

The answer is -233.15° C

-

Explanation:

We know,

0 Kelvin = -273.15° C

So, 40 K = (-273.15+40) = -233.15° C

If my answer helps then please mark me brainliest.

Answer:

-233.15'C

Explanation:

The density of oil is 0.8 g/cm^3. What is the mass of 36 cm^3 of oil? + (1 Point) O 0.29 N O 28.09 28.8 g O 36.89​

Answers

Answer:

density = mass/volume

density=0.8

volume=36

mass=?

0.8=mass/36

mass = 36x0.8=28.8g

Which formula is used to find an object's acceleration?
Ο α= Δί - Δν
Ο α= Δv+ Δ
Ο α=Δyl Δί
α= Δ / Δν

Answers

Answer:

4 option is correct ........

A free-fall parachutist eventually reaches a top speed where air resistance prevents further acceleration. What name is given to this ‘top speed'?

Answers

The name given to it is "terminal velocity".

In reality, it isn't a velocity, and it doesn't happen in free-fall.

Go figure.

Which will a positively charged object attract

Answers

Positively charged objects and neutral objects attract each other. hope this helped!
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