1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
romanna [79]
3 years ago
7

A eutectic alloy is which of the following (two correct answers): (a) the composition in an alloy system at which the two elemen

ts are present in equal proportions, (b) the composition in an alloy system for which the solidus and liquidus are at different temperatures, (c) the composition in an alloy system for which the solidus and liquidus are at the same temperature, (d) the composition in an alloy system that has the highest melting point, and (e) the composition in an alloy system that has the lowest melting point?
Engineering
1 answer:
NeTakaya3 years ago
3 0

Answer:

Option (c) and option (d)

Explanation:

Eutectic system is one in which a solid and homogeneous mixture of two or more substances resulting in the formation of super lattice is formed which can melt or solidify at a temperature lower than the melting point of any individual metal.

Eutectic alloys are those which have its components mixed in a specific ratio.

It is the composition in an alloy system for which both the  liquidus and solidus temperatures are equal.

Eutectic alloys have the composition in which the melting point of the metal is lower than the other alloy composition.

You might be interested in
Bryan a project manager and his team have been assigned a new project. The team members have already started working on their as
Vedmedyk [2.9K]

Answer:

there teams management is good

4 0
3 years ago
Given: A graphite-moderated nuclear reactor. Heat is generated uniformly in uranium rods of 0.05m diameter at the rate of 7.5 x
sineoko [7]

Answer:

The maximum temperature at the center of the rod is found to be 517.24 °C

Explanation:

Assumptions:

1- Heat transfer is steady.

2- Heat transfer is in one dimension, due to axial symmetry.

3- Heat generation is uniform.

Now, we consider an inner imaginary cylinder of radius R inside the actual uranium rod of radius Ro. So, from steady state conditions, we know that, heat generated within the rod will be equal to the heat conducted at any point of the rod. So, from Fourier's Law, we write:

Heat Conduction Through Rod = Heat Generation

-kAdT/dr = qV

where,

k = thermal conductivity = 29.5 W/m.K

q = heat generation per unit volume = 7.5 x 10^7 W/m³

V = volume of rod = π r² l

A = area of rod = 2π r l

using these values, we get:

dT = - (q/2k)(r dr)

integrating from r = 0, where T(0) = To = Maximum center temperature, to r = Ro, where, T(Ro) = Ts = surface temperature = 120°C.

To -Ts = qr²/4k

To = Ts + qr²/4k

To = 120°C + (7.5 x 10^7 W/m³)(0.025 m)²/(4)(29.5 W/m.°C)

To = 120° C + 397.24° C

<u>To = 517.24° C</u>

5 0
3 years ago
I'm a grandma my Samuel needs to be tough in math what do I do
Sedbober [7]
Well you could always do what Hispanics do and repeat the question 2-3 times while yelling till they finally answer
7 0
3 years ago
Read 2 more answers
Air is compressed by a 40-kW compressor from P1 to P2. The air temperature is maintained constant at 25°C during this process a
AlexFokin [52]

Answer:

the rate of entropy change of the air is -0.1342 kW/K

the assumptions made in solving this problem

- Air is an ideal gas.

- the process is isothermal ( internally reversible process ). the change in internal energy is 0.

- It is a steady flow process

- Potential and Kinetic energy changes are negligible.

Explanation:

Given the data in the question;

From the first law of thermodynamics;

dQ = dU + dW ------ let this be equation 1

where dQ is the heat transfer, dU is internal energy and dW is the work done.

from the question, the process is isothermal ( internally reversible process )

Thus, the change in internal energy is 0

dU = 0

given that; Air is compressed by a 40-kW compressor from P1 to P2

since it is compressed, dW = -40 kW

we substitute into equation 1

dQ = 0 + ( -40 kW )

dQ = -40 kW

Now, change in entropy of air is;

ΔS_{air = dQ / T

given that T = 25 °C = ( 25 + 273.15 ) K = 298.15 K

so we substitute

ΔS_{air =  -40 kW / 298.15 K

ΔS_{air =  -0.13416 ≈ -0.1342 kW/K

Therefore, the rate of entropy change of the air is -0.1342 kW/K

the assumptions made in solving this problem

- Air is an ideal gas.

- the process is isothermal ( internally reversible process ). the change in internal energy is 0.

- It is a steady flow process

- Potential and Kinetic energy changes are negligible.

7 0
2 years ago
(a) In your own words, explain how donor impurities in semiconductors give rise to free electrons in numbers in excess of those
Kazeer [188]

Answer:

A. N type impurities

B. P type impurities

Explanation:

A. The impurities contribute free electrons and changing the conducting property of the semi conductor. When a pentavalent impurities in a semi conductor( impurities with five valence electron) , the impurity atom replace some of the semi conductor atoms in the crystal structure where 4 of the valence electron would be involved in bonding of 4 neighbouring semiconductor while leaving the fifth electron to be free(negative charge carrier) which is available for detachment.

B. When a trivalence impurity is added to semiconductor, instead of excess electron, there will be excess hole created by crystals. Reason for this attribute is the trivalence atom will replace some tetra valence semiconductor atom, when three valence electrons of the 3 valence electrons of the trivalent impurity atom make bond with three neighbouring semiconductor which gives rise to lack of electron in the bond of the fourth neighbouring semiconductor which contribute a whole to the crystalline since trivalent impurity contribute excess holes to the crystal of semi conductor, this holes can accept electrons.

8 0
3 years ago
Other questions:
  • After a 65 newton weight has fallen freely from rest a vertical distance of 5.3 meters, the kinetic energy of the weight is
    12·1 answer
  • For an irreversible isothermal process occured in a system with temperature T, which following expression best evaluates the cha
    11·1 answer
  • Consider a step pn junction made of GaAs at T = 300 K. At zero bias, only 20% of the total depletion region width is in the p-si
    11·1 answer
  • Why is data driven analytics of interest to companies?
    9·1 answer
  • A train travels 650 meters in 25 seconds. What is the train's velocity?
    9·1 answer
  • A 1/20 scale model of a wing is used to determine forces on the actual airplane. the 1/20 scale refers to the:_____
    10·2 answers
  • I need help on the Coderz Challenge missions 3 part 3. PLEASE HELP!
    11·2 answers
  • Define extensive and intensive properties of thermodynamic system.
    5·2 answers
  • How deep is a 6ft hole?​
    14·2 answers
  • Which of the following is NOT associated with Urban Sprawl?
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!