Queuing Theory Formulas

Important formulas for Queuing Theory(Acc. to GATE requirement):

No. of People in the system,    Ns =   λ  / (μ- λ )


No. of People in Queue,             Nq = Ls - λ  / μ =  λ  / (μ- λ ) -   λ  / μ
                                                    =  λ ^2 / μ(μ- λ )


Average waiting time in system,  Ws = Ns/ λ  = 1/(μ- λ )


Average waiting time in queue,    Wq = Nq/ λ  =  λ / μ(μ- λ )


Complete Queuing Theory is quite versatile but this much of formulas are sufficient for GATE

We know a reversible adiabatic process is an isentropic process......but  is an isentropic process necessarily a reversible adiabatic process. Why or why not?

Types of fluids

The Hershel- Buckley fluids are known as Thixotropic fluid, while Bingham fluids are know as Ideal Plastic fluids.

                          General equation is      τ =     μ  .[] ^ n  +  τ0 

1)     For Bingham and Thixotropic fluids, τ0 is greater than zero.

2)     For all other fluids, τ0 = 0

3)     For newtonian fluids, τ0  is zero and value of exponent n is 1.

4)     For Pseudoplastic and Thixotropic fluids, n<1.

5)     For Dilatant fluids, n> 1.

Equal amounts of Water at 80 deg C and water at 0 deg C are mixed together. What would be the final temperature of mixture? What will be change in answer if water at 0 deg C is in form of ice?

There are two power-plants, Nuclear power plant and Thermal Power Plant. Using same conditions, which of these would be having more efficiency?

Hint: Producing Nuclear energy, energy of 2 out of 3 Neutrons is absorbed during chain reaction.

What is the effect on power generated, efficiency when we make a boiler super critical? 

A power plant working based upon Rankine cycle, is designed to run in winters. Now it is operated in summers. Now what would happen to efficiency; it decrease, increase on remain same?

What is the diff between torque and bhp and which one will have a greater effect on top speed and acceleration figures?
have heard that diesel engines r more torquier by nature. why??

say i have 2 cars one which has 10 x of torque and 20 bhp and the other has 20x of torque and 10 bhp.
which car will be quicker??