Answer:
The entropy change of the air is 
Explanation:

is unknown
we can apply the following expression to find 


now substitute

To find entropy change of the air we can apply the ideal gas relationship
Δ

Δ

Δ
Answer:
a = 1.68m/
Explanation:
Please kindly find the attached file for explanations
Answer:
There are six conditions
1. Poles should contain some residual flux.
2. Field and armature winding must be correctly connected so that initial mmm adds residual flux.
3. Resistance of field winding must be less than critical resistance.
4. Speed of prime mover of generator must be above critical speed.
5. Generator must be on load.
6. Brushes must have proper contact with commutators.
Explanation:
Answer:
B. $5.18
Explanation:
Cost of electricity per kWh = $0.09
Power consumption of refrigerator = 320W = 320/1000 = 0.32kW
In a month (30 days) the refrigerator works 1/4 × 30 days = 7.5 days = 7.5 × 24 hours = 180 hours
Energy consumed in 180 hours = 0.32kW × 180h = 57.6kWh
Cost of electricity of 57.6kWh energy consumed by the refrigerator = 57.6 × $0.09 = $5.18