Why is low voltage advantageous in arc welding?

Cho biết tác dụng chung của các hệ giằng khung ngang nhà công nghiệp nhẹ 1 tầng 1 nhịp.

Dmitry_Shevchenko [17]

I don’t know how to speak the laungue or know this language

4 0

2 years ago

The density of a certain type of steel is 8.1 g/cm3. What is the mass of a 100 cm3 chunk of this steel

irina1246 [14]

Answer:

810 g

Explanation:

Mass is the product of density and volume:

m = ρV

m = (8.1 g/cm³)(100 cm³) = 810 g

The mass of the chunk is 810 grams.

4 0

2 years ago

In the ____ sector; occupations range from maintenance/service technicians, light vehicle technicians, and heavy vehicle technic

Len [333]

Answer:

B

Explanation:

becuase this is the best optimal answer when it comes to this particular situation of choice

5 0

1 year ago

The exhaust steam from a power station turbine is condensed in a condenser operating at 0.0738 bar(abs). The surface of the heat

lozanna [386]

Answer:

Percentage change 5.75 %.

Explanation:Given ;

Given

Pressure of condenser =0.0738 bar

Surface temperature=20°C

Now from steam table

Properties of steam at 0.0738 bar

Saturation temperature corresponding to saturation pressure =40°C

$h_f= 167.5\frac{KJ}{Kg},h_g= 2573.5\frac{KJ}{Kg}$

So Δh=2573.5-167.5=2406 KJ/kg

Enthalpy of condensation=2406 KJ/kg

So total heat=Sensible heat of liquid+Enthalpy of condensation

$Total\ heat\ =C_p\Delta T+\Delta h$

Total heat =4.2(40-20)+2406

Total heat=2,544 KJ/kg

Now film coefficient before inclusion of sensible heat

$h_1=\dfrac{\Delta h}{\Delta T}$

$h_1=\dfrac{2406}{20}$

$h_1=120.3\frac{KJ}{kg-m^2K}$

Now film coefficient after inclusion of sensible heat

$h_2=\dfrac{total\ heat}{\Delta T}$

$h_2=\dfrac{2,544}{20}$

$h_2=127.2\frac{KJ}{kg-m^2K}$

$So\ Percentage\ change=\dfrac{h_2-h_1}{h_1}\times 100$

$=\dfrac{127.2-120.3}{120.3}\times 100$

=5.75 %

So Percentage change 5.75 %.

3 0

2 years ago

A transmission line (TL) of length L and conductance per unit length G' is connected to an ideal constant voltage generator V. T

Andru [333]

Answer:

The Current will decrease by a factor of 2

Explanation:

Given the conditions, it should be noted that the current in the circuit is determined by the LOAD. In other words, the amount of current generator will be producing depends upon the load connected to it.

Now, as the question says, the load is reduced to half its original value, we can write:

$P1 = \sqrt{3} (V) (I1) Cos\alpha ----- (1)$

$P2 = \sqrt{3} (V) (I2) Cos\alpha\\$

Since, P2 = P1/2,

$P1/2 = \sqrt{3} (V) (I2) Cos\alpha ----- (2)\\$

Dividing equations (1) and (2), we get,

P1 / (P1/2) = I1/ I2

$I2 = I1 / 2\\$

Hence, it is proved that the current in the transmission line will decrease by a factor of 2 when load is reduced to half.

7 0

2 years ago