GIVEN:
Amplitude, A = 0.1mm
Force, F =1 N
mass of motor, m = 120 kg
operating speed, N = 720 rpm
[tex]\frac{A}{F}[/tex] = [tex]\frac{0.1\times 10^{-3}}{1} = 0.1\times 10^{-3}[/tex]
Formula Used:
[tex]A = \frac{F}{\sqrt{(K_{t} - m\omega ^{2}) +(\zeta \omega ^{2})}}[/tex]
Solution:
Let Stiffness be denoted by 'K' for each mounting, then for 4 mountings it is 4K
We know that:
[tex]\omega = \frac{2 \pi\times N}{60}[/tex]
so,
[tex]\omega = \frac{2 \pi\times 720}{60}[/tex] = 75.39 rad/s
Using the given formula:
Damping is negligible, so, [tex]\zeta = 0[/tex]
[tex]\frac{A}{F}[/tex] will give the tranfer function
Therefore,
[tex]\frac{A}{F}[/tex] = [tex] \frac{1}{\sqrt{(4K - 120\ ^{2})}}[/tex]
[tex]0.1\times 10^{-3}[/tex] = [tex] \frac{1}{\sqrt{(4K - 120\ ^{2})}}[/tex]
Required stiffness coefficient, K = 173009 N/m = 173.01 N/mm
Product service life is determined by a. estimates b. market forces c. liability d. property tests e. failure analysis f. all of the above
Answer: d) property tests
Explanation: Product service life can be referred as the life that define the service that can be provided by the product manufactured.The service life contains the testing and calculation of the product's quality, reliability, maintenance factor etc. These factors are known as the property of the product and so is calculated by the property test. Therefore option (d) is the correct option because other option does not define the factors for defining the product service life.
The specific heat of aluminum is approximately 900 J/kg°C. If the temperature of a 5 kg specimen needs to be raised from 30°C to 1000°C, the amount of heat required will be equal to Select one: a)- 4365 kJ b)- 4365 Btu c)- 4365W d)- None of the above
Answer:
a) 4365 kJ
Explanation:
In any thermodynamic system, any heat change is accompanied by the change in temperature. The relation between heat released/gained in a system and the temperature is:
Q=mcΔT
where,
Q is the amount of heat absorbed or released
m is the mass
ΔT is the change in temperature
c is called the specific heat.
Specific heat is defined as heat gained by 1 unit mass of any sample to raise the temperature of the sample by 1 °Celsius.
Thus, from the question:
Mass of aluminum =5 kg
Final temperature = 1000°C
Initial temperature = 30°C
ΔT = (1000 -30)°C = 970°C
Specific heat of aluminum = 900 J/kg°C
Thus, Amount of heat required:
Q = 5 kg×900 J/kg°C×970°C = 4365000 J
The conversion of J into kJ is shown below:
1 J = 10⁻³ kJ
Thus, Heat gained by aluminum =4365000 ×10⁻³ J = 4365 kJ
The pressure at any point in a static fluid depends only on the Select one a)- depth, surface pressure, and specific weight. b)- specific weight. c)- surface pressure and depth. d)- depth and container shape
Answer:
c). surface pressure and depth
Explanation:
We know that fluid pressure is measured in two different ways namely --
1. Pressure measured above complete vacuum or absolute zero is called Absolute Pressure.
2.Pressure measured above atmospheric pressure is called Gauge Pressure.
In the figure below, we can find the pressure at the point A in the static fluid inside the tank which is at a depth of h from the water surface.
Let the atmospheric pressure which is acting on the water surface be [tex]P_{atm}[/tex].
Let ρ be the density of water and g be the acceleration due to gravity.
Therefore we know that pressure at a point in a fluid is
P = ρ[tex]\times[/tex]g[tex]\times[/tex]h
Therefore total pressure acting on the point A in a fluid is
[tex]P_{tot}[/tex] = [tex]P_{atm}[/tex] + P
[tex]P_{tot}[/tex] = [tex]P_{atm}[/tex] + ρ[tex]\times[/tex]g[tex]\times[/tex]h
Thus, pressure at a point A in a static fluid depends on the surface pressure and the depth of the point from the free surface.
From your cooling load (8890.007 Btu/hr = 2.605kW, determine mass flow rate of refrigerants. Use the following "rule of thumb" estimate of a standard room of size 180 ft^2: 1 ton of refrigerant = 12,000Btu = 3.517 kW Rule of thumb: 1 ton cooling load = 300-400 ft^2
Answer:
0.740833917 ton/hr
Explanation:
Given:
Cooling load, 8890.007 Btu/hr = 2.605 kW
Room size = 180 [tex]ft^{2}[/tex]
According to the thumb rule
1 ton of refrigerant = 12000Btu
Hence for 8890.007 Btu/hr,
the mass flow rate of the refrigerant is =8890.007 / 12000
= 0.740833917 ton per hr
Hence, mass flow rate is 0.740833917 ton/hr
A roller support acts like a contact boundary condition as it can produce a reaction force as a push response to a body but will not produce a pull force to hold a body from moving away. a)True b)- False
Answer:
a) True
Explanation:
Roller can provide reaction for push support but it can not provide reaction for pull support.
From the free body diagram of roller and hinge support we can easily find that ,Roller providing vertical reaction and can not provide horizontal reaction.
On the other hand hinge support can provide reaction in both the direction.
So we can say that roller can not proved reaction for pull support.
An aircraft increases its speed by 2% in straight and level flight. If the total lift remains constant determine the revised CL as a percentage of its original value to three significant figure
Answer:
96.1%
Explanation:
We know that lift force
[tex]F_L=\dfrac{1}{2}C_L\rho AV^2[/tex]
------------(1)
Where [tex]C_L[/tex] is the lift force coefficient .
ρ is the density of fluid.
A is the area.
V is the velocity.
Now when speed is increased by 2 % and all other parameter remains constant except [tex]C_L[/tex] .
Let;s take new value of lift force coefficient is [tex]C_L'[/tex] .
[tex]F_L=\dfrac{1}{2}C_L'\rho A(1.02V)^2[/tex]
-----------(2)
Now from equation 1 and 2
[tex]C_L\times V^2=C_L'\times1.0404 V^2[/tex]
⇒[tex]C_L'=0.961C_L[/tex]
So we can say that revised value of lift force coefficient is 96.1% of original value.
In a quasi-static process, the system remains infinitesimally close to equilibrium throughout the process. a)True b) False
Answer:
It is True that in a quasi static process, the system remains infinitesimally close to equilibrium state throughout the process.
Explanation:
The literal meaning of the word "quasi" is 'almost' and static is 'rest', so quasi static state means almost at rest state of the system
It can be further explained as the process, in thermodynamics which allows the system to be carried to slowly to maintain its equilibrium or to remain in its internal equilibrium state. Such a process is known as quasi-static process. Such processes also allow all isothermal and adiabatic processes to operate slowly so as not to disturb their internal equilibrium. this makes the system to always remain in thermal equilibrium
Thin film deposition is a process where: a)-elemental, alloy, or compound thin films are deposited onto a bulk substrate! b)-Phosphatization is also applied c)-Zinc plating is also applied d)-None of the above
Answer:
(A) elemental, alloy, or compound thin films are deposited on to a bulk substrate
Explanation:
In film deposition there is process of depositing of material in form of thin films whose size varies between the nano meters to micrometers onto a surface. The material can be a single element a alloy or a compound.
This technology is very useful in semiconductor industries, in solar panels in CD drives etc
so from above discussion it is clear that option (a) will be the correct answer
An electric heater draws 12 A from a 120 V power source. How much powe heater dissipate? (a) 10 W (b) 1200 W (c) 1440 W (d) 17,280 W
Answer:
c) 1440 W
Explanation:
P = V*i = (12A)*(120V) = 1440W
According to the scenario, the amount of power that is dissipated by the heater is 1440 W. Thus, the correct option for this question is C.
What is Power?Power may be defined as the amount of energy that is significantly transferred or converted per unit of time. The unit of power is the watt (W). It may be typically calculated with the help of the given formula:
P = W/Δt.According to the context of this question, the amount of power that is dissipated within the heater is calculated by the following formula:
P = V × i = 12 × 120 = 1440 W.Therefore, according to the scenario, the amount of power that is dissipated by the heater is 1440 W. Thus, the correct option for this question is C.
To learn more about Power, refer to the link:
https://brainly.com/question/1634438
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List the main activities of exploration??
Answer: Exploration includes plethora of activities and depend upon the kind of exploration a person is doing. But most include some of the basic activities like research , investigation, planning and execution.
Suppose we want to explore new petroleum sites then we would have to start with studying the geography of that area, then according to our research we will analyse the hot spots or the sector where probability of finding of oil field is highest, post that appropriate man power is skilled professionals, tools and machinery will be brought at the site so that execution can take place.
What are units for heating capacity? Mark all that apply: a)- Tons b)- kJ/kg c)- kW d)- Btu
Answer:
(b) kJ/kg
Explanation:
The ratio of amount of energy required to change the temperature of the substance by certain magnitude and this magnitude of temperature change is known as heat capacity of the substance.
The expression for Heat capacity is:
C=E/ΔT
Where,
C is the Heat capacity
E is the energy absorbed/released
ΔT is the change in temperature
The SI unit of heat capacity is J/K.
(a) Tons represents the unit of mass (1000 kg)
(c) kW represents the unit of power (1000 W)
(d) Btu represents the unit of heat (1055 J)
The units from the options that can be a unit of heat capacity is (b) kJ/kg.
If the compound swivel base is set on 60 degrees at the lathe centerline index, how many degrees will the reading be at the cross slide index? A. 45 B. 150 C. 30 D. 90
Answer:
C.30°
Explanation:
Given that compound swivel base is set on 60° at the lathe center line index.
We need to find reading on cross slide index
We know that relationship between center line index and cross slide index in angle 2∝=β
Where ∝ Angle of swivel and β is the reading on cross line index.
So by using above relationship between center line index and cross slide index
2∝=60°⇒∝=30°
So our option is C.
A gas contained within a piston-cylinder undergoes the follow change in states: Process 1: Constant volume from p1 = 1 bar V1 = 2.6 m3 to state 2 with p2 = 2.7 bar Process 2: Compression to V3 = 1.5 m3, which the pressure-volume relationship is pV = constant. Process 3: Constant pressure to state 4, where V4 = 0.5 m3. Sketch the processes on p-V graph and evaluate the work for each process in kJ.
Answer:
Process 1:W=0
Process 2:W= -386.13 KJ
Process 3:W= -468 KJ
Explanation:
Process 1:[tex]P_1=1 bar,V_1=2.6m^3[/tex]
Process 2:[tex]P_2=2.7bar,V_2=2.6m^3[/tex]
Process 3:[tex]V_3=1.5 m^3[/tex]
[tex]V_4=0.5 m^3[/tex]
Process 1:
Work (W)=0 ,because it is constant volume process.
Process 2:
It is constant temperature process so PV=C
[tex]P_2V_2=P_3V_3[/tex]
[tex]P_3=\dfrac{P_2V_2}{V_3}[/tex]
[tex]P_3=\dfrac{2.7\times 2.6}{1.5}[/tex]
[tex]P_3=4.68 [/tex]bar
So work in constant temperature process
W=[tex]P_2V_2\ ln\dfrac{V_3}{V_2}[/tex]
W=[tex]270\times 2.6\ ln\dfrac{1.5}{2.6}[/tex] (1 bar=100KPa)
W= -386.13 KJ
Negative sign means it is compression process.
Process 3:
It is a constant pressure.
So work W=[tex]P_3(V_4-V_3)[/tex]
W=468(0.5-1.5) KJ
W= -468 KJ
Negative sign means it is compression process.
The response of an inductor to current is most directly similar to the response of the capcitor (a) current (b) voltage (c) resistance (d) inductor
Answer:
(b) vpltage
Explanation:
we know the expression for voltage across the inductor V=L[tex]\frac{di}{dt}[/tex] which clearly shows voltage across the inductor is directly proportional to rate of change of current similarly current across the capacitor I=C[tex]\frac{dv}{dt}[/tex] from the expression we can see that current across the capacitor is directly proportional to rate of change of voltage. so from above discussion it is clear that response of an iductor to current is similar to response of capacitor to voltage
The difference between absolute viscosity and kinematic viscosity is a. the absolute viscosity is the mass density divided by the kinematic viscosity c. absolute viscosity relates absolute pressure, film thickness and velocity while kinematic viscosity b. the kinematic viscosity is the absolute viscosity divided by the mass density relates shear stress and relative pressure e. all of the above
Answer:
b).the kinematic viscosity is absolute viscosity divided by mass density
Explanation:
Viscosity is a fluid property that offers resistance or obstruction to deformation or fluid flow.
Viscosity is of two types--
1. Absolute viscosity , μ
2. Kinematic viscosity, ν
Absolute viscosity :
Absolute viscosity is also called the dynamic viscosity. It is the internal resistance of the fluid to flow.
Kinematic viscosity :
Kinematic viscosity is the ratio of dynamic viscosity to the density of the fluid.
Absolute viscosity measures a fluid's internal friction, while kinematic viscosity is the ratio of absolute viscosity to the fluid's density. Viscosity affects how easily a liquid flows; higher intermolecular forces lead to higher viscosity, and this property is critical in fluid dynamics studies.
Explanation:The difference between absolute viscosity and kinematic viscosity is that absolute viscosity, often referred to simply as viscosity, represents the fluid's resistance to flow and is a measure of the internal friction within the fluid. Kinematic viscosity, on the other hand, takes the fluid's density into account and is the ratio of the fluid's absolute viscosity to its density. While absolute viscosity is measured in units like Pascal-seconds (Pa·s), kinematic viscosity is measured in square meters per second (m²/s).
Viscosity is influenced by intermolecular forces; liquids that can flow easily, such as ethanol, have lower viscosities, while substances like motor oil with higher intermolecular forces have higher viscosities. Measuring the time it takes for steel balls to fall through a fluid or for a fluid to flow through a narrow tube helps determine the fluid's viscosity. In other words, absolute viscosity is concerned with the sheer strength and flow resistance of a fluid, while kinematic viscosity relates to the movement of the fluid under the force of gravity considering its volume.
What is/are the benefit(s) of short fibre reinforcements? A)Increased stiffness only. B)Increased strength and increased Toughness. C) Increased Toughness and increased flexibility. D) None of the above.
Answer: B) Increased strength and increased toughness
Explanation: Short fibre reinforcement has the major property of being tough and has high strength. Short fibre reinforcement is basically a process of addition of the short fibre to the thermoplastic materials to make the improvement in their quality and working by increasing their strength.They also have application in many areas because of their hardness property as well as being cost -effective. Thus, the option (b) is the correct option.
In the SI system of units, the absolute temperature is measured to be 303 K Its value in Fahrenheit is a-) 76 F b)- 86F c)-79 F d)- 82 F
Answer:
The correct answer is option B i.e. 86 f
Explanation:
The freezing point of water is 32°f and boiling point is 212 °f. Thus difference in boiling and freezing point is exactly come out to be 180°. therefore fahrenheit scale is 1/180 interval of both scale ( freezing and boiling point)
given data:
absolute temperature is 303 K
We know by general formula of temperature in fahrenheit
°F = [tex]\frac{9}{5}[/tex] × (K-273) +32
°F = [tex]\frac{9}{5}[/tex] × (303-273) +32
°F = 86 F
A lake contains water at a maximum depth of 237.3 meters. This water has a density of 989 kg/m3 and the acceleration due to gravity at this location is 9.806 m/s2. The air above the water has a barometric pressure of 29.83 in of Hg where the altitude correct for pressure is -1.87 in of Hg to get absolute pressure. What is the absolute pressure at the bottom of the lake?
Answer:690.21 mm of Hg
Explanation:
Given data
depth of lake[tex]\left (h\right )[/tex]=237.3m
density of lake water[tex]\left ( \rho\right )[/tex]=[tex]989kg/m^3[/tex]
acceleration due to gravity[tex]\left ( g\right )[/tex]=[tex]9.806m/s^2[/tex]
air above water has a barometric pressure of 29.83in of Hg=711.2 mm of Hg
Altitude correct for pressure=1.87in of Hg=47.5 mm of Hg
Absolute pressure above water =711.2-47.5mm of Hg=663.7 mm of Hg
Absolute pressure at bottom of Lake=Pressure at surface level +[tex]\left ( \rho \times g\times h\right )[/tex]
Absolute pressure at bottom of Lake=663.7+[tex]\frac{989\times 9.81\273.3}{10^{5}}[/tex]
Absolute pressure at bottom of Lake=690.21 mm of Hg
A(n)_____ is a device that provides the power and motion to manipulate the moving parts of a valve or damper used to control fluid flow. A. actuator B. pilot-operated regulator C. ratio regulator D. sliding stem
Answer:
Out of the four options provided
option A. actuator
is correct
Explanation:
An actuator is the only device out of the four mentioned devices that provides power and ensures the motion in it in order to manipulate the movement of the moving parts of the damper or a valve used whereas others like ratio regulator are used to regulate air or gas ratio and none mof the 3 remaining options serves the purpose
What is the theoretical density in g/cm3 for Lead [Pb]?
Answer:
11.34 g/cm3
Explanation:
At room temperature, where it is in a solid state, it is 11.34 [tex]\frac{g}{cm^{3}}[/tex]. While at melting temperature, at 327.5 ° C, it is 10.66 [tex]\frac{g}{cm^{3}}[/tex]
In shaft design, this of the following has the least influence on the shaft diameter to be determined: (a) Shaft deflection (b) Bearing type (c) Factor of safety (d) Rotational speed of the shaft
Answer: (d)Rotational speed of the shaft
Explanation: Shaft design is the design of a shaft that is used for defining the stresses at certain critical part of shaft. The shaft design has shaft diameter as a major part and this is determined by several factors like type of bearing , deflection, torque,safety factor etc.
But the least important factor for determining of the diameter is the rotational speed because it defines the rotation of an object around a particular axis, where is it states about the number of turns divisible by time. Therefore option(d) is the correct option.
The resistivity of mercury drops suddenly to zero at a critical temperature, maki mercury a superconductor below that temperature. ( True , False )
Resistance zero meaning superconductor, so True.
Is it possible that two types of dislocation coexist. a)-True b)- False
Answer:
yes it is possible
Explanation:
dislocation are if two type edge and screw dislocations
edge dislocation is a defect where an extra half plane is inside the lattice.
and screw dislocation is one in which can be assumed as the first half of the crystal slips over another.
These dislocation can coexist together where the line direction and burger vectors are neither parallel nor perpendicular then at that condition both dislocation screw and edge will coexist
Give two methods on how powder is produced in powder metallurgy.
Answer:
Explanation:
Atomization using gas streamMolten metal is forced through a small orifice and is shatter by a jet of compressed air,inert gas .
In Atomization, the particles shape is analysed by the rate of solidification and varies from spherical to highly irregular shape.
Reductionoxide of metals are transformed to pure metal powder when undefended to under melting point gases results in a product of spongy material.
It is used for Iron,copper,tungsten,Nickel etc.
Answer:
(1)Atomizing process
(2)Gaseous reduction
Explanation:
The first step in powder metallurgy is the production of powder,because the property of the final product depends on the powder.
The methods for the production of powder are as follow
(1)Atomizing process
(2)Gaseous reduction
(1)Atomizing process:
In the Atomizing process the molten metal is passing through an orifice into a stream of inert gas.Due to this rapid cooling of metal occurs and then it will in very fine particle .
(2)Gaseous reduction:
In this process powder is producing by grinding of metallic oxide to a fine state,after that reducing it by carbon mono oxide.
A pendulum has an oscillation frequency (T) which is assumed to depend upon its length (L), load mass (m) and the acceleration of gravity (g). Determine the relationship between oscillation frequency, length, load mass and acceleration of gravity. Differentiate as well which variable does not affect the oscillation frequency.
Answer:
Mass does not affect oscillation frequency.
Explanation:
Let the bob of the pendulum makes a small angular displacement θ. When the pendulum is displaced from the equilibrium position, a restoring force tries to act upon it and it tries to bring the pendulum back to its equilibrium position. Let this restoring force be F.
Therefore, F = -mgsinθ
Now for pendulum, for small angle of θ,
sinθ[tex]\simeq[/tex]θ
Therefore, F = -mgθ
Now from Newton's 2nd law of motion,
F = m.a = -mgθ
[tex]\Rightarrow m.\frac{d^{2}x}{dt^{2}} = - mg\Theta[/tex]
Now since, x = θ.L
[tex]\Rightarrow L.\frac{d^{2}\Theta }{dt^{2}}= -g\Theta[/tex]
[tex]\Rightarrow \frac{d^{2}\Theta }{dt^{2}}= -\frac{g}{L}.\Theta[/tex]
[tex]\Rightarrow \frac{d^{2}\Theta }{dt^{2}}+\frac{g}{L}.\Theta =0[/tex]
Therefore, angular frequency
[tex]\omega ^{2}[/tex] = [tex]\frac{g}{L}[/tex]
ω = [tex]\sqrt{\frac{g}{L}}[/tex]
Also we know angular frequency is , ω = 2.π.f
where f is frequency
Therefore
2πf = [tex]\sqrt{\frac{g}{L}}[/tex]
f = [tex]\frac{1}{2 \pi }\sqrt{\frac{g}{L}}[/tex]
So from here we can see that frequency,f is independent of mass, hence it does not affect frequency.
A circular plate with diameter of 20 cm is placed over a fixed bottom plate with a 1 mm gap between two plates filled with Kerosene at 40 degree C, shown in the following figure. Find the torque needed to rotate the top plate at 5 rad/s. The velocity distribution in the gap is linear and the shear stress on the edge of the rotating plate can be neglected.
Answer:
T = 1.17 x [tex]10^{-3}[/tex] N-m
Explanation:
Given :
Gap between the two plates , dy = 1 mm
dy = 1 x [tex]10^{-3}[/tex] m
Angular velocity of the top plate , ω = 5 rad/s
Diameter of the plate, D = 20 cm
Radius of the plate, R = 10 cm
= 0.1 m
Temperature of the kerosene = 40°C
Viscosity of kerosene at 40°C = 0.0015 Pa-s
Now let us take a small elemental ring of thickness dr at a radius r.
Therefore, area of this elemental ring of dr = 2πrdr
Now linear velocity at radius r = ω x r
5r m/s
Now applying Newtons law of viscosity we get,
Shear stress, τ = μ.[tex]\frac{du}{dy}[/tex]
[tex]\Rightarrow \frac{F_{s}}{A}=\mu .\frac{du}{dy}[/tex]
[tex]\Rightarrow \frac{F_{s}}{A}=\mu .\frac{5r-0}{1\times 10^{-3}}[/tex]
[tex]\Rightarrow \frac{F_{s}}{A}=\mu \times 10^{3}\times 5r[/tex]
[tex]F_{s}=\mu \times 10^{3}\times 5r\times 2\pi rdr[/tex]
[tex]F_{s}=5 \times 10^{3}\times \mu \times r\times 2\pi rdr[/tex]
[tex]F_{s}=\frac{18849}{400}\times r^{2}dr[/tex]
Now we know torque due to small strip,
dT = [tex]F_{s}[/tex] x r
dT = [tex]\frac{18849}{400}\times r^{3}dr[/tex]
Therefore total torque for r=0 to r=R can be calculated. So by integrating,
[tex]\int dT=\int_{0}^{R}\frac{18849}{400}\times r^{3}dr[/tex]
[tex]T = \frac{18849}{400}\times \frac{R^{4}}{4}[/tex]
[tex]T = 47.1225\times \frac{0.1^{4}}{4}[/tex]
T = 1.17 x [tex]10^{-3}[/tex] N-m
If the specific gravity of a fluid is 0.721, its mass density is a. 44.99 lb/ft3 -b. 44.99 slugs/ft. c. 1.397 lb/ft d. 1.397 slugs/t e. none of these 11. A fluid a. is a gas. b. is a liquid. _c. is incompressible d. has a definite volume regardless of the size of the container e. a. and b. above.
Answer:
mass density of fluid is = 1000*0.721 = 721 kg/m3
so option e is correct
11. option e is correct ( a and b).
Explanation:
given data
specific gravity of fluid = 0.721
we know that mas density of water [tex]{\gamma _{water}}[/tex] is 1000 kg/m3
specific gravity of water is given as S.G
[tex]S.G = \frac{\gamma _{fluid} }{\gamma _{water}}[/tex]
mass density of fluid is = 1000*0.721 = 721 kg/m3
A fluid is combined form used for gas and liquid.
it offer negligible resistance to stress (shear stress)
Microchips found inside most electronic devices today are examples of what material A. Polymers B. Alloys C. Composites D. None of the above. E. Metals
Answer: A
Explanation:
Microchips are made out of silicone witch is a polymer.
Answer:
its a
Explanation:
Intrinsic semiconduction is a property of a pure material. (True , False )
True.
An intrinsic semiconductor is a pure semiconductor. At room temperature it behaves as an insulator because it only has a few free and hollow electrons due to thermal energy.
In an intrinsic semiconductor there are also electron fluxes and gaps, although the total current resulting is zero. This is because the action of thermal energy produces free electrons and gaps in pairs, so there are as many free electrons as there are gaps with which the total current is zero.
Heat conduction is a function of material property, temperature difference and fluid the geometry of the object. a) True b) False
Answer:
a)True
Explanation:
According to Fourier's law,It states that Heat transfer is directly proportionate to the temperature gradient.For unidirectional conduction
[tex]q''\alpha\dfrac{dT}{dx}[/tex]
Where q'' is the heat flux.
When This directly proportionate is remove then one constant will on that place and that constant is called conductivity of material.
[tex]q''=K\dfrac{dT}{dx}[/tex]
So total heat transfer Q
[tex]Q=KA\dfrac{dT}{dx}[/tex]
When conductivity (K) of material is not constant
K=[tex]K_0[/tex](a+bT) where a,b are constant.
So from the above expression we can say that heat transfer in material will depend on temperature difference,material property and on on geometry of object.