Answer:
A. optical isolation
Explanation:
well I can't really give a good explanation because I also saw the same question in my exams and option A was the correct answer
 
        
             
        
        
        
Answer:
   il(t) = e^(-100t)
Explanation:
The current from the source when the switch is closed is the current through an equivalent load of 15 + 50║50 = 15+25 = 40 ohms. That is, it is 80/40 = 2 amperes. That current is split evenly between the two parallel 50-ohm resistors, so the initial inductor current is 2/2 = 1 ampere.
The time constant is L/R = 0.20/20 = 0.01 seconds. Then the decaying current is described by ...
   il(t) = e^(-t/.01)
   il(t) = e^(-100t) . . . amperes
 
        
             
        
        
        
ANSWERS:

Explanation:
Given:
 Piston cylinder assembly which mean that the process is constant pressure process P=C.
<u>AMMONIA </u>
state(1) 
saturated vapor 
The temperature 
Isothermal process  
a) 
 ( double)
 ( double)
b)
 (reduced by half)
 (reduced by half)
To find the final state by giving the quality in lbf/in we assume the friction is neglected and the system is in equilibrium.
state(1)
using PVT data for saturated ammonia 

then the state exists in the supper heated region.
a) from standard data



assume linear interpolation


b)

from standard data 

then the state exist in the wet zone 

