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3 years ago

A circuit with -diameter connecting wires at a _ temperature will have the least electrical resistance.

Engineering

1 answer:

ELEN [110]3 years ago

7 0

Answer:

2. high or low

Explanation:

A circuit with high-diameter connecting wires at a low temperature will have the least electrical resistance.

According to Ohm's law, the current flowing through a current carrying conductor is directly proportional to the potential difference across its terminal and inversely proportional to resistance at a constant temperature.

Mathematically, V = IR.

Where;

V = Voltage

I = Current

R = Resistance

Some of the factors affecting resistance of a wire are;

- The resistance of a conducting wire is inversely proportional to its cross-sectional area (diameter).

- The resistance of a conducting wire is directly proportional to its temperature.

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Consider uniaxial extension of a test specimen. It has gauge length L = 22 cm (the distance between where it is clamped in the t

Katena32 [7]

Answer:

A) 4800.6 N

B) 0.2255 mm/min

C) 8.6792 inches

Explanation:

Given data :

gauge Length = 22 cm = 220 mm

cross section diameter/thickness = 1.8 mm

young's modulus ( E ) = 205 GPa

Ultimate tensile strength ( σu ) = 420MPa

Time = 2 mins

A) what force would fracture the specimen

σU = Ff /A

where A (area) = thickness * width ( unknown ) hence we assume a width of 6.35 mm

Ff = σU × A = 420 * 1.8 * 6.35 = 4800.6 N

B) calculate the strain rate

Ultimate tensile strength ( σU ) = εE

ε = σU / E = 420/205000 = 0.00205

also ε = ΔL / Li = ( Lf - Li) / Li = (Lf / Li) - 1

therefore ε + 1 = (Lf / Li) = 1 + 0.00205 = 1.00205

Li = gauge length = 220 mm

Hence : Lf = 1.00205 × gauge length = 1.00205 * 220 = 220.451 mm

strain rate

(Lf - Li) / Time = (0.451) / 2 min = 0.2255 mm/min

C) Elongation in inches prior to fracture

ΔL = ε × Li = 0.451 mm

Lf = 220 mm + 0.451 mm = 220.451 mm = 8.6792 inches

3 0

3 years ago

What is the purpose of a heater core

aliina [53]

A heater core is a radiator-like device used in heating the cabin of a vehicle. Hot coolant from the vehicle's engine is passed through a winding tube of the core, a heat exchanger between coolant and cabin air.

Explanation:

4 0

3 years ago

Read 2 more answers

Write a program that asks the user for the name of a file. The program should display the number of words that the file contains

Flura [38]

Answer:

import java.io.*;

import java.util.Scanner;

public class CountWordsInFile {

public static void main(String[] args) throws IOException {

Scanner keyboard = new Scanner(System.in);

System.out.print("Enter file name: ");

String fileName = keyboard.next();

File file = new File(fileName);

try {

Scanner scan = new Scanner(file);

int count = 0;

while(scan.hasNext()) {

scan.next();

count += 1;

}

scan.close();

System.out.println("Number of words: "+count);

} catch (FileNotFoundException e) {

System.out.println("File " + file.getName() + " not present ");

System.exit(0);

}

3 0

4 years ago

What is the difference between the pressure head at the end of a 150m long pipe of diameter 1m coming from the bottom of a reser

uysha [10]

Answer:

$\frac {p_2- p_1}{\rho g} = 31.06 m$

Explanation:

from bernoulli's theorem we have

$\frac{p_1}{\rho g} + \frac{v_1^{2}}{2g} +z_1 = \frac{p_2}{\rho g} + \frac{v_2^{2}}{2g} +z_2 + h_f$

we need to find pressure head difference i.e.

$\frac {p_2- p_1}{\rho g} = (z_1 - z_2) - h_f$

where h_f id head loss

$h_f = \frac{flv^{2}}{D 2g}$

velocity v = $\frac{1}{n} * R^{2/3} S^{2/3}$

$S = \frac{\delta h}{L} = \frac{40}{150} = 0.267$

hydraulic mean radius R = $\frac{A}{P} = \frac{hw}{2h+w}$

$R = \frac{40*1}{2*40+1} = 0.493 m$

so velocity is = $\frac{1}{0.013} * 0.493^{2/3} 0.267^{1/2}$

v = 24.80 m/s

head loss

$h_f = \frac{0.0019*150*24.80^{2}}{1* 2*9.81}$

$h_f =8.93 m$

pressure difference is

$\frac {p_2- p_1}{\rho g} = 40 - 8.93 = 31.06 m$

$\frac {p_2- p_1}{\rho g} = 31.06 m$

4 0

3 years ago

One kg of an idea gas is contained in one side of a well-insulated vessel at 800 kPa. The other side of the vessel is under vacu

laiz [17]

Answer:

Option C = internal energy stays the same.

Explanation:

The internal energy will remain the same or unchanged because this question has to do with a concept in physics or classical chemistry (in thermodynamics) known as Free expansion.

So, the internal energy will be equals to the multiplication of the change in temperature, the heat capacity (keeping volume constant) and the number of moles. And in free expansion the internal energy is ZERO/UNCHANGED.

Where, the internal energy, ∆U = 0 =quantity of heat, q - work,w.

The amount of heat,q = Work,w.

In the concept of free expansion the only thing that changes is the volume.

7 0

4 years ago

A circuit with ____ -diameter connecting wires at a _____ temperature will have the least electrical resistance.

A circuit with -diameter connecting wires at a _ temperature will have the least electrical resistance.