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2 years ago

What Advantage does a voltmeter have over a noncontact voltage indicator when testing for voltage

Engineering

1 answer:

galina1969 [7]2 years ago

5 0

Answer:

Obviously you shouldn't rely just on the meter for your safety. You'd disconnect wall fuses or kill main switches before you start, using the meter just gives you some extra protection: with the meter you might notice for example that you've disconnected the wrong fuse and the unit is still live.

Explanation:

Hope it helps! :)

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Prompt the user to enter five numbers, being five people's weights. Store the numbers in an array of doubles. Output the array's

atroni [7]

Answer:

See below in the explanation section the Matlab script to solve the problem.

Explanation:

prompt='enter the first weight w1: ';

w1=input(prompt);

wd1=double(w1);

prompt='enter the second weight w2: ';

w2=input(prompt);

wd2=double(w2);

prompt='enter the third weight w3: ';

w3=input(prompt);

wd3=double(w3);

prompt='enter the fourth weight w4: ';

w4=input(prompt);

wd4=double(w4);

prompt='enter the first weight w5: ';

w5=input(prompt);

wd5=double(w5);

x=[wd1 wd2 wd3 wd4 wd5]

format short

6 0

3 years ago

Design a PLC ladder logic program to control the operation of a conveyor-storage system using the following sequence: - 1. Progr

Phantasy [73]

Answer:

See explaination

Explanation:

Kindly check attachment for the step by step solution of the given problem.

8 0

3 years ago

When converting liquid level units to sensor output signal units, you should first convert the liquid level units to _____ units

dangina [55]

The answer is 2 because I just took the test!

7 0

1 year ago

Verify if 83 is a term in the arithmetic sequence 11,15,19,23

EleoNora [17]

Answer:

yes, it is

Explanation:

The sequence: (+4)

23,27,31,35,39,43,47,51,55,59,63,67,71,75,79,83

Hope this helps! :)

3 0

3 years ago

Water at atmospheric pressure boils on the surface of a large horizontal copper tube. The heat flux is 90% of the critical value

masya89 [10]

Answer:

The tube surface temperature immediately after installation is 120.4°C and after prolonged service is 110.8°C

Explanation:

The properties of water at 100°C and 1 atm are:

pL = 957.9 kg/m³

pV = 0.596 kg/m³

ΔHL = 2257 kJ/kg

CpL = 4.217 kJ/kg K

uL = 279x10⁻⁶Ns/m²

KL = 0.68 W/m K

σ = 58.9x10³N/m

When the water boils on the surface its heat flux is:

$q=0.149h_{fg} \rho _{v} (\frac{\sigma (\rho _{L}-\rho _{v})}{\rho _{v}^{2} } )^{1/4} =0.149*2257*0.596*(\frac{58.9x10^{-3}*(957.9-0.596) }{0.596^{2} } )^{1/4} =18703.42W/m^{2}$

For copper-water, the properties are:

Cfg = 0.0128

The heat flux is:

qn = 0.9 * 18703.42 = 16833.078 W/m²

$q_{n} =uK(\frac{g(\rho_{L}-\rho _{v}) }{\sigma })^{1/2} (\frac{c_{pL}*deltaT }{c_{fg}h_{fg}Pr } \\16833.078=279x10^{-6} *2257x10^{3} (\frac{9.8*(957.9-0.596)}{0.596} )^{1/2} *(\frac{4.127x10^{3}*delta-T }{0.0128*2257x10^{3}*1.76 } )^{3} \\delta-T=20.4$

The tube surface temperature immediately after installation is:

Tinst = 100 + 20.4 = 120.4°C

For rough surfaces, Cfg = 0.0068. Using the same equation:

ΔT = 10.8°C

The tube surface temperature after prolonged service is:

Tprolo = 100 + 10.8 = 110.8°C

8 0

3 years ago