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katrin [286]
3 years ago
11

?Why the efficiency of Class A amplifier is very poor​

Engineering
1 answer:
horsena [70]3 years ago
6 0
Sorry not sure about that
You might be interested in
For better thermal control it is common to make catalytic reactors that have many tubes packed with catalysts inside a larger sh
Paul [167]

Answer:

the  pressure drop  is 0.21159 atm

Explanation:

Given that:

length of the reactor L = 2.5 m

inside diameter of the reactor d= 0.025 m

diameter of alumina sphere dp= 0.003 m

particle density  = 1300 kg/m³

the bed void fraction \in =  0.38

superficial mass flux m = 4684 kg/m²hr

The Feed is  methane with pressure P = 5 bar and temperature T = 400 K

Density of the methane gas \rho = 0.15 mol/dm ⁻³

viscosity of methane gas \mu = 1.429  x 10⁻⁵ Pas

The objective is to determine the pressure drop.

Let first convert the Density of the methane gas from 0.15 mol/dm ⁻³  to kg/m³

SO; we have :

Density =  0.15 mol/dm ⁻³  

Molar mass of methane gas (CH₄) = (12 + (1×4) ) = 16 mol

Density =  0.1 5 *\dfrac{16}{0.1^3}

Density =  2400

Density \rho_f =  2.4 kg/m³

Density = mass /volume

Thus;

Volume = mass/density

Volume of the methane gas =  4684 kg/m²hr / 2.4 kg/m³

Volume of the methane gas = 1951.666 m/hr

To m/sec; we have :

Volume of the methane gas = 1951.666 * 1/3600 m/sec = 0.542130 m/sec

Re = \dfrac{dV \rho}{\mu}

Re = \dfrac{0.025*0.5421430*2.4}{1.429*10^5}

Re=2276.317705

For Re > 1000

\dfrac{\Delta P}{L}=\dfrac{1.75 \rho_f(1- \in)v_o}{\phi_sdp \in^3}

\dfrac{\Delta P}{2.5}=\dfrac{(1.75 *2.4)(1- 0.38)*0.542130}{1*0.003 (0.38)^3}

\Delta P=8575.755212*2.5

\Delta = 21439.38803 \ Pa

To atm ; we have

\Delta P = \dfrac{21439.38803 }{101325}

\Delta P =0.2115903087  \ atm

ΔP  ≅  0.21159 atm

Thus; the  pressure drop  is 0.21159 atm

4 0
3 years ago
How much extra water does a 21.5 ft, 175-lb concrete canoe displace compared to an ultra-lightweight 38-lb Kevlar canoe of the s
pantera1 [17]

Answer:

The volume of the extra water is 2.195 ft^{3}

Solution:

As per the question:

Mass of the canoe, m_{c} = 175 lb + w

Height of the canoe, h = 21.5 ft

Mass of the kevlar canoe, m_{Kc} = 38 lb + w

Now, we know that, bouyant force equals the weight of the fluid displaced:

Now,

V\rho g = mg

V = \frac{m}{\rho}                                  (1)

where

V = volume

\rho = 62.41 lb/ft^{3} = density

m = mass

Now, for the canoe,

Using eqn (1):

V_{c} = \frac{m_{c} + w}{\rho}

V_{c} = \frac{175 + w}{62.41}

Similarly, for Kevlar canoe:

V_{Kc} = \frac{38 + w}{62.41}

Now, for the excess volume:

V = V_{c} - V_{Kc}

V = \frac{175 + w}{62.41} - \frac{38 + w}{62.41} = 2.195 ft^{3}

8 0
3 years ago
You will create three classes, the first two being Student and LineAtOfficeHour. The instances of the first class defines a sing
White raven [17]

Answer:

Complete solution is given below:

Explanation:

//student class

class Student{

  private String firstname,lastname;

 

  //constructor

  Student(String first,String last){

      this.firstname=first;

      this.lastname=last;

  }

 

  //getters and setters

  public String getFirstname() {

      return firstname;

  }

  public void setFirstname(String firstname) {

      this.firstname = firstname;

  }

  public String getLastname() {

      return lastname;

  }

  public void setLastname(String lastname) {

      this.lastname = lastname;

  }

  //function to get the fullname of student

  public String fullName() {

      return this.firstname+" "+this.lastname;

  }

}

//class for line at office hour

class LineAtOfficeHour{

 

  private Student line[];

  private int N=0;

  private int back=0;

 

  //empty constructor

  LineAtOfficeHour() {

      line=new Student[5];

  }

  //parameterized constructor

  LineAtOfficeHour(Student st[]) {

      int i=0;

      line=new Student[5];

      while(i<st.length && i<5) {

          line[i]=st[i];

          i++;

      }

      this.N=i;

      this.back=i-1;

  }

  //function to check if line is empty or not

  public boolean isEmpty() {

      if(this.N==0)

          return true;

      else

          return false;

  }

  //function to check if line is full

  public boolean isFull() {

      if(this.N==5) {

          return true;

      }else

          return false;

  }

  ///function to get the size of line

  public int size() {

      return this.N;

  }

 

  //function to add a student to the line

  public void enterLine(Student s) {

      if(isFull())

          System.out.println("Line is full!!!!");

      else {

          line[++back]=s;

          this.N++;

      }

  }

  public Student seeTeacher() {

      Student result=null;

      if(this.N>=0) {

          result=line[0];

          int i=0;

          for(i=1;i<N;i++) {

              line[i-1]=line[i];

          }

          line[i-1]=null;

          this.N--;

          this.back--;

      }

     

     

      return result;

  }

  //function to print students in line

  public String whosInLine() {

      String result ="";

      for(int i=0;i<this.N;i++) {

          result+=line[i].fullName()+",";

      }

      return result;

  }

}

//driver method

public class TestLine {

  public static void main(String[] args) {

      LineAtOfficeHour list=new LineAtOfficeHour();

     

      if(list.isEmpty()) {

          System.out.println("Line is empty!!!!!!!!!");

      }

     

      Student s1[]=new Student[3];

      s1[0]=new Student("John","Smith");

      s1[1]=new Student("Sam","Zung");

      s1[2]=new Student("Peter","Louis");

      list=new LineAtOfficeHour(s1);

     

      if(list.isEmpty()) {

          System.out.println("Line is empty!!!!!!!!!");

      }else {

          System.out.println("Line is not empty.........");

      }

     

      System.out.println("Students in line: "+list.whosInLine());

     

      System.out.println("Student removed: "+list.seeTeacher().fullName());

     

      System.out.println("Students in line: "+list.whosInLine());

  }

}

6 0
4 years ago
Entropy change is evaluated using Eq. 6.2a based on an internally reversible process. Can the entropy change between two states
Vadim26 [7]

Answer:

YES

Explanation:

Entropy is an extensive property of the system entropy change that value of entropy change can be determined for any process between the states whether reversible or not. i have attached the formula to calculate entropy change which is independent of whether the system is reversible or not and can be determined for any process.

4 0
4 years ago
Assume you have four fins, each with a mass of 8.0 grams. What is the total weight of these four fins? (Hint: watch your units!)
soldier1979 [14.2K]
The answer is 32.0 grams
7 0
3 years ago
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