Answer:
This band gap also allows semiconductors to convert light into electricity in photovoltaic cells and to emit light as LEDs when made into certain types of diodes. Both these processes rely on the energy absorbed or released by electrons moving between the conduction and valence bands.
Explanation:
On the internet
Answer:
1090 Steel >1040 Steel > Pure aluminium >Diamond.
Explanation:
Toughness:
Toughness can be define as the are of load -deflection diagram up to fracture point.
Modulus of toughness can be defines as the area of stress-strain diagram up to fracture point.Modulus of toughness is the property of material.
So the decreasing order of toughness can be given as follows
1090 Steel >1040 Steel > Pure aluminium >Diamond.
Answer:
The minimum mass flow rate will be "330 kg/s".
Explanation:
Given:
For steam,
For water,
They add energy efficiency as condenser becomes adiabatic, with total mass flow rate of minimal vapor,
⇒ 
On putting the estimated values, we get
⇒ 
⇒ 
⇒ 
Answer:
COP of the heat pump is 3.013
OP of the cycle is 1.124
Explanation:
W = Q₂ - Q₁
Given
a)
Q₂ = Q₁ + W
= 15 + 7.45
= 22.45 kw
COP = Q₂ / W = 22.45 / 7.45 = 3.013
b)
Q₂ = 15 x 1.055 = 15.825 kw
therefore,
Q₁ = Q₂ - W
Q₁ = 15.825 - 7.45 = 8.375
∴ COP = Q₁ / W = 8.375 / 7.45 = 1.124
Answer:
18 kJ
Explanation:
Given:
Initial volume of air = 0.05 m³
Initial pressure = 60 kPa
Final volume = 0.2 m³
Final pressure = 180 kPa
Now,
the Work done by air will be calculated as:
Work Done = Average pressure × Change in volume
thus,
Average pressure = 
= 120 kPa
and,
Change in volume = Final volume - Initial Volume = 0.2 - 0.05 = 0.15 m³
Therefore,
the work done = 120 × 0.15 = 18 kJ
