Answer:
The main sections included in the bill of quantities are Form of Tender, Information, Requirements, Pricing schedule, Provisional sums, and Day works.
Answer:
Information technology is important in our lives because it helps to deal with every day's dynamic things. Technology offers various tools to boost development and to exchange information. Both these things are the objective of IT to make tasks easier and to solve many problems.
Answer:
0.304 L of Freon is needed
Explanation:
Q = mCT
Q is quantity of energy that must be removed = 47 BTU = 47×1055.06 = 49587.82 J
C is specific heat of Freon = 74 J/mol.K = 74 J/mol.K × 1 mol/120 g = 0.617 J/g.K
T is temperature in the area of Mars = 189 K
m = Q/CT = 49587.82/(0.617×189) = 452.23 g = 452.24/1000 = 0.45223 kg
Density of Freon = specific gravity of Freon × density of water = 1.49 × 1000 kg/m^3 = 1490 kg/m^3
Volume of Freon = mass/density = 0.45223/1490 = 0.000304 m^3 = 0.000304×1000 = 0.304 L
Given Information:
Balanced Y-Y three phase circuit
Phase Voltage = Van = 120 < 10° V
Load Impedance = Zy = 20 +j15 Ω = 25 < 36.86° Ω
Required Information:
Load Voltages = Vab, Vbc, Vca = ?
Line currents = Ia, Ib, Ic = ?
Answer:
Vab = 208 < 40°
Vbc = 208 < -80°
Vca = 208 < 160°
Ia = 4.8 < -26.86°
Ib = 4.8 < -146.86°
Ic = 4.8 < 93.14°
Explanation:
Since it is balanced 3 phase system, all phases have equal magnitude and 120° phase shift
Van = 120 < 10° V
Vbn = 120 < -110° V
Vcn = 120 < 130° V
In a Y connected system, the phase voltage and line voltage are related as
Vab =
(Van) <+30°
Vab =
*120<10°+30°
Vab = 208 < 40°
Vbc = 208 < -80°
Vca = 208 < 160°
In a Y connected circuit, Iphase = Iline
Ia = Van/Zy
Ia = 120 < 10°/25 < 36.86°
Ia = 4.8 < -26.86°
Ib = 4.8 < -146.86°
Ic = 4.8 < 93.14°