1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
vovikov84 [41]
3 years ago
9

A system has a level 1 cache and a level 2 cache. The hit rate of the level 1 cache is 90% and the hit rate of the level 2 cache

is 80%. An access to level 1 cache requires 1 cycle, an access to level 2 cache requires 4 cycles, and an access to main memory requires 50 cycles. What is the average access time?
(A) 1.32
(B) 2.22
(C) 5.26
(D) 19.32
Engineering
1 answer:
Hatshy [7]3 years ago
6 0

Answer:

B) 2.22

Explanation:

In a first step, the system will look in cache number 1. If it is not found in cache number 1, then the system will look in cache number 2. Finally (if not in cache 2 also) the system will look in main memory.

The average access time will take into consideration success in cache 1, failure in cache number 1 but success in cache number 2, failure in cache number 1 and 2 but success in main memory.

Mathematically we can write it into the following equation :

AAT=(H1.T1)+(1-H1).H2.T2+(1-H1).(1-H2).Hm.Tm

Where AAT is the average access time

H1,H2 and Hm are the hit rate of cache 1,cache 2 and main memory respectively.

T1,T2 and Tm are the access time of cache 1, cache 2 and main memory respectively

Hm = 1

AAT=(0.9).(1)+(1-0.9).(0.8).(4)+(1-0.9).(1-0.8).(1).(50)=0.9+0.32+1=2.22

AAT=2.22

Therefore, option b) is the correct.

You might be interested in
Indicate whether the following statements are true or false for an isothermal process: (A) Q=T(∆S). (B) ∆U=0.(C) The entropy cha
Lena [83]

Answer:

A=False

B=False

C=False

D=False

E=False

F=False

Explanation:

A. In an isothermal process, only the reversibly heat transfer is 0, Q_{rev}=T (\Delta S)

B. Consider the phase change of boiling water. Here, the temperature remains constant but the internal energy of the system increases.

C. This is not true even in reversible process, as can be inferred from the equation in part A.

D. This is only true in reversible processes, but not in all isothermal processes.

E. Consider the phase change of freezing water. Here, the surroundings are increasing their entropy, as they are taking in heat from the system.

F. This is not true if (\Delta U)\neq 0, like in answer B. One case where this is true is in the reversible isothermal expansion (or compression) of an ideal gas.

3 0
3 years ago
Creating vacancies in ceramics. Consider doping ZrO2 with small concentrations of Nb205. The valence of Nb is 5. Assume that Nb
Murljashka [212]

Answer:

Creating vacancies in ceramics. Consider doping ZrO₂ with small concentrations of Nb205. The valence of Nb is 5. Assume that Nb ions sit in Zr ion sites

a. A substitutional defect will be produced.

b. With this dopping, the Nb increases electron band conduction and decreases oxygen anion conduction in ZrO₂.

Explanation:

(a) The defect produced by dopping a little concentration of Nb₂O5 with Nb in the +5 charge state is known as a substitutional defect.

(b) With this dopping, the Nb increases electron band conduction and decreases oxygen anion conduction in ZrO₂.

Moreover, if oxygen vacancies are rate-limiting defect, the corrosion of ZrO₂ decreases and if electrons are rate-limiting then the corrosion of ZrO₂ is accelerated.

7 0
4 years ago
A steel cylindrical pressure vessel has an inside diameter of 2m and a wall thickness of 2cm. If the steel has a yield stress Y
Feliz [49]

Answer:

The pressure that will cause yielding in the tank in the longitudinal direction is 1.7 Mpa

Explanation:

We are dealing with a thin-walled pressure vessel here.

the formula for calculating the hoops stress of this pressure vessel is \sigma =P d/4t

\sigma Y = longitudinal yield stress = 425  \times 10^{6} Pa

Thickness = 2/1000 =0.002m

Outside diameter = inside siameter + thickness =  2m + 0.002m= 2.002m

Dm = Mean diameter = Outside diameter - thickness = 2.002 - 0.002 = 2m

P= 425 \times 10^{6} \times 4 \times 0.002 /2=1.7 Mpa

4 0
3 years ago
In an aligned and continuous carbon fiber-reinforced nylon 6,6 composite, the fibers are to carry 97% of a load applied in the l
Juli2301 [7.4K]

Answer:

a) 0.26

b) 1077 MPa

Explanation:

a) The following equation can be used to determine the volume fraction:

\frac{F_f}{F_m} =\frac{E_fV_f}{E_m(1-V_f)}

\frac{0.97}{1-0.97} =\frac{260V_f}{2.8(1-V_f)}

32.3 = \frac{260V_f}{2.8-2.8V_f}

V_f = 0.26

b) Tensile strength can be found by using the following equation:

\sigma_{cl} = \sigma_m(1-V_f)+\sigma_fV_f = 50*(1-0.26)+4000*0.26 = 1077 MPa

5 0
4 years ago
If E = 94.2 mJ of energy is transferred when Q = 1.66 C of charge flows through a circuit element, what is the voltage across th
Anni [7]

Answer:

V = 56.8 mV

Explanation:

When a current I flows across a circuit element, if we assume that the dimensions of the circuit are much less than the wavelength of the power source creating this current, there exists a fixed relationship between the power dissipated in the circuit element, the current I and the voltage V across it, as follows:

P = V*I

By definition, power is the rate of change of energy, and current, the rate of change of the charge Q, so we can replace P and I, as follows:

E/t = V*q/t ⇒ E = V*Q

Solving for V:

V = E/Q = 94.2 mJ /1.66 C = 56.8 mV

6 0
3 years ago
Other questions:
  • A horizontal curve is to be designed for a two-lane road in mountainous terrain. The following data are known: Intersection angl
    7·1 answer
  • Vitrification is a process of: a. Chemical reaction bonding of aggregate ceramic powder b. Cementing aggregate ceramic powder wi
    9·1 answer
  • What is the relationship between orifice diameter and pipe diameter​
    15·1 answer
  • One kilogram of air, initially at 5 bar, 350 K, and 3 kg of carbon dioxide (CO2), initially at 2 bar, 450 K, are confined to opp
    14·1 answer
  • A sky diver with a mass of 70 kg jumps from an aircraft. The aerodynamic drag force acting on the sky diver is known to be FD =k
    9·1 answer
  • Which statement is true about what will happen when the example code runs?1: main PROC2: mov edx,03: mov eax,404: push eax5: cal
    10·1 answer
  • A hair dryer is basically a duct in which a few layers of electric resistors are placed. A small fan pulls the air in and forces
    13·1 answer
  • What is the mechanical advantage of a simple block and tackle with one rope?
    7·2 answers
  • Economics is the study of how individuals and societies make choices under the condition of
    10·1 answer
  • Technician A says that the definition of torque is how far the crankshaft twists in degrees.Technician B says that torque can re
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!