Answer:74.75 kJ/kg
Explanation:
Given
mass of hot fluid
=5 kg/s
Energy associated with it=150 kJ/kg
mass of cold fluid
=15 kg/s
Energy associated with it=50 kJ/kg
Energy lost=5.5 kW
Let the Enthalpy of outlet fluid be h
mass at outlet
![m=m_l+m_h=20 kg/s](https://tex.z-dn.net/?f=m%3Dm_l%2Bm_h%3D20%20kg%2Fs)
Using Energy Conservation
![m_h\times E_h+m_l\times E_l+Q=m\times h](https://tex.z-dn.net/?f=m_h%5Ctimes%20E_h%2Bm_l%5Ctimes%20E_l%2BQ%3Dm%5Ctimes%20h)
![5\times 150+15\times 50-5.5=20\times h](https://tex.z-dn.net/?f=5%5Ctimes%20150%2B15%5Ctimes%2050-5.5%3D20%5Ctimes%20h)
h=74.75 kJ/kg
Answer:
Differential analysis is used when it is needed to determine the detail information of the flow i.e. pressure or stress variation along any point.
Explanation:
In fluid mechanics, sometime situation arise in which we need to determine in detail about flow characteristics like stress and pressure variation.
To find these flow characteristics some relationship need to imply either at a point or at very small volume and analysis of flow at very small point is known as differential analysis.
Example: pressure and shear stress variation in a line of the wing of a plane.
Answer:
Pumps converts mechanical energy into hydraulic energy while turbines convert hydraulic energy into mechanical energy.
Explanation:
The machines which converts and transfers mechanical energy in the form of torque on the shaft into hydraulic energy in the form of water under pressure are called pumps whereas those machines which converts water pressure or hydraulic energy into mechanical energy that is further converted into electrical energy are called turbines.
The pump impeller rotates in the opposite direction to the turbine runner.
A turbine delivers work as output whereas a pump consumes work.
First law of thermodynamics for a pump :
W = ( H₁-H₂) +Q , where H₁ > H₂
First law of thermodynamics for a turbines :
W = ( H₂-H₁) +Q , where H₁ < H₂
Answer:
a) The forward voltage is 0.23 V
b) The current that flows
Explanation:
The forward voltage is the minimum voltage that must be applied to a diode before it starts to conduct. The equation is given by:
a) At what forward voltage does a diode conduct a current equal to 10,000 Is ? In terms of Is
![I_{d} = I_{s}(e^{\frac{v_{f} }{0.025} }-1)](https://tex.z-dn.net/?f=I_%7Bd%7D%20%3D%20%20I_%7Bs%7D%28e%5E%7B%5Cfrac%7Bv_%7Bf%7D%20%7D%7B0.025%7D%20%7D-1%29)
Where:
Id is the diode current = 10000Is,
Vd is the forward voltage at which the diode begins to conduct,
Is is the saturation current.
![I_{d} = I_{s}(e^{\frac{v_{f} }{0.025} }-1)](https://tex.z-dn.net/?f=I_%7Bd%7D%20%3D%20%20I_%7Bs%7D%28e%5E%7B%5Cfrac%7Bv_%7Bf%7D%20%7D%7B0.025%7D%20%7D-1%29)
![10000I_{s} = I_{s}(e^{\frac{v_{f} }{0.025} }-1)](https://tex.z-dn.net/?f=10000I_%7Bs%7D%20%3D%20%20I_%7Bs%7D%28e%5E%7B%5Cfrac%7Bv_%7Bf%7D%20%7D%7B0.025%7D%20%7D-1%29)
Dividing through by Is,
![10000 = (e^{\frac{v_{f} }{0.025} }-1)](https://tex.z-dn.net/?f=10000%20%3D%20%20%28e%5E%7B%5Cfrac%7Bv_%7Bf%7D%20%7D%7B0.025%7D%20%7D-1%29)
![10000 +1= e^{\frac{v_{f} }{0.025} }](https://tex.z-dn.net/?f=10000%20%2B1%3D%20%20e%5E%7B%5Cfrac%7Bv_%7Bf%7D%20%7D%7B0.025%7D%20%7D)
![10001= e^{\frac{v_{f} }{0.025} }](https://tex.z-dn.net/?f=10001%3D%20%20e%5E%7B%5Cfrac%7Bv_%7Bf%7D%20%7D%7B0.025%7D%20%7D)
Taking the natural logarithm of both sides,
![ln(10001)= {\frac{v_{f} }{0.025} }](https://tex.z-dn.net/?f=ln%2810001%29%3D%20%20%7B%5Cfrac%7Bv_%7Bf%7D%20%7D%7B0.025%7D%20%7D)
![9.21= {\frac{v_{f} }{0.025} }](https://tex.z-dn.net/?f=9.21%3D%20%20%7B%5Cfrac%7Bv_%7Bf%7D%20%7D%7B0.025%7D%20%7D)
multiplying through by 0.025
= 0.23 V
The forward voltage does a diode conduct a current equal to 10,000 Is is 0.23 V
b) what current flows in the same diode when its forward voltage is 0.7 V?
![I_{d} = I_{s}(e^{\frac{v_{f} }{0.025} }-1)](https://tex.z-dn.net/?f=I_%7Bd%7D%20%3D%20%20I_%7Bs%7D%28e%5E%7B%5Cfrac%7Bv_%7Bf%7D%20%7D%7B0.025%7D%20%7D-1%29)
![I_{d} = I_{s}(e^{\frac{0.7}{0.025} }-1)](https://tex.z-dn.net/?f=I_%7Bd%7D%20%3D%20%20I_%7Bs%7D%28e%5E%7B%5Cfrac%7B0.7%7D%7B0.025%7D%20%7D-1%29)
![I_{d} = I_{s}(1.45*10^{12} -1)](https://tex.z-dn.net/?f=I_%7Bd%7D%20%3D%20%20I_%7Bs%7D%281.45%2A10%5E%7B12%7D%20-1%29)
![I_{d} = (1.45*10^{12}I_{s})A](https://tex.z-dn.net/?f=I_%7Bd%7D%20%3D%20%20%281.45%2A10%5E%7B12%7DI_%7Bs%7D%29A)