Answer:
a) Ql=33120000 kJ
b) COP = 5.6
c) COPreversible= 29.3
Explanation:
a) of the attached figure we have:
HP is heat pump, W is the work supplied, Th is the higher temperature, Tl is the low temperature, Ql is heat supplied and Qh is the heat rejected. The worj is:
W=Qh-Ql
Ql=Qh-W
where W=2000 kWh
Qh=120000 kJ/h

b) The coefficient of performance is:

c) The coefficient of performance of a reversible heat pump is:

Th=20+273=293 K
Tl=10+273=283K
Replacing:

Answer:
0.0659 A
Explanation:
Given that :
( saturation current )
at 25°c = 300 k ( room temperature )
n = 2 for silicon diode
Determine the saturation current at 100 degrees = 373 k
Diode equation at room temperature = I = Io 
next we have to determine the value of V at 373 k
q / kT = (1.6 * 10^-19) / (1.38 * 10^-23 * 373) = 31.08 V^-1
Given that I is constant
Io =
= 0.0659 A
Answer:
Time =t2=58.4 h
Explanation:
Since temperature is the same hence using condition
x^2/Dt=constant
where t is the time as temperature so D also remains constant
hence
x^2/t=constant
2.3^2/11=5.3^2/t2
time=t^2=58.4 h
Answer:
8 mm
Explanation:
Given:
Diameter, D = 800 mm
Pressure, P = 2 N/mm²
Permissible tensile stress, σ = 100 N/mm²
Now,
for the pipes, we have the relation as:
where, t is the thickness
on substituting the respective values, we get
or
t = 8 mm
Hence, the minimum thickness of pipe is 8 mm