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
Viktor [21]
3 years ago
10

The high electrical conductivity of copper is an important design factor that helps improve the energy efficiency of electric mo

tors. This is important because motors and motor-driven systems are significant consumers of electricity, accounting for 43% - 46% of all global electricity consumption and 69% of all electricity used by industry. Inefficient motors waste electrical energy and are indirect contributors to greenhouse gas emissions. ElectroSpark, Inc. has been developing a new copper die-cast rotor technology specifically for premium efficiency motors, replacing the standard aluminum rotor. There are multiple reasons for doing so, including the possibility that the motor will consume less energy. They designed an experiment to test their idea in a common ¾ Horse power (HP) motor that is normally manufactured with an aluminum rotor. They designed a copper rotor that fit in their ¾ HP motor housing and ran a production line for a day producing the motors. They randomly selected 20 copper-rotor motors from that output and 20 aluminum-rotor motors produced from the same line the day before. These 40 motors were all run for 8 hours a day for 30 days and the energy consumed was measured in total Kilowatt Hours (example data below, using alpha=.05):
Copper: 560.145 539.673 556.834 559.873
Aluminium: 564.674 573.912 553.385 574.078
What is the correct hypothesis to test the problem described in this scenario?
A. H0: μD (copper-aluminum) ≥ 0; H1: μD (copper-aluminum) < 0
B. H0: μ_copper – μ_aluminum ≥ 0; H1: μ_copper – μ_aluminum < 0
C. H0: μD (copper-aluminum) ≥ 0; H1: μD (copper-aluminum) > 0
D. H0: μ_copper – μ_Aluminum ≤ 0; H1: μ_copper – μ_aluminum > 0
Engineering
1 answer:
ludmilkaskok [199]3 years ago
5 0

Answer:

B

Explanation:

This is a two sample t-test and not a matched pair t-test

null hypothesis(H0) will be that mean energy consumed by copper rotor motors is greater than or equal to mean energy consumed by aluminium rotor motors

alternate hypothesis(H1) will be that mean energy consumed by copper rotor motors is less than or equal to mean energy consumed by aluminium rotor motors.

So, option D is rejected

The hypothesis will not compare mean of differences of values of energy consumed by copper rotor motor and aluminium rotor motor.

Option A and C are also rejected

You might be interested in
Differentiate between isohyetal method and arithmetical average method of rainfall​
prohojiy [21]

Answer:

Explained below

Explanation:

The isohyetal method is one used in estimating Rainfall whereby the mean precipitation across an area is gotten by drawing lines that have equal precipitation. This is done by the use of topographic and other data to yield reliable estimates.

Whereas, the arithmetic method is used to calculate true precipitation by the way of getting the arithmetic mean of all the points or arial measurements that will be considered in the analysis.

7 0
3 years ago
Technician a says that if a tapered roller bearing is adjusted to loose
Effectus [21]
The technician is true
5 0
3 years ago
YO CUTIE! HELP MEEEEEE! Hazardous waste is a category that includes all of the following EXCEPT
madam [21]

your answer should be <u>B. Soluble</u>

3 0
2 years ago
Read 2 more answers
A Carnot cooler operates with COP = 11, whose ambient temperature is 300K. Determine the temperature at which the refrigerator a
SashulF [63]

Answer:

275 Kelvin

Explanation:

Coefficient of Performance=11

T_H=\text {Absolute Temperature of high temperature reservoir=300 K}

T_L=\text {Absolute Temperature of low temperature reservoir}

\text {Coefficient of performance for carnot cooler}\\=\frac {T_L}{T_H-T_L}\\\Rightarrow 11=\frac{T_L}{300-T_L}\\\Rightarrow 11(300-T_L)=T_L\\\Rightarrow 3300-11T_L=T_L\\\Rightarrow 3300=T_L+11T_L\\\Rightarrow 3300=12T_L\\\Rightarrow T_L=\frac {3300}{12}\\\Rightarrow T_L=275\ K\\\Therefore \text{Temperature at which the refrigerator absorbs heat=275 Kelvin}

8 0
3 years ago
What are the well-known effects of electricity​
Sever21 [200]

Answer:

Hence, the three effects of electric current are heating effect, magnetic effect and chemical effect.

3 0
3 years ago
Read 2 more answers
Other questions:
  • 1. Looking at the case study provided under the Companion Material section, what is the main problem that is addressed in this c
    13·1 answer
  • What is a magnitute?
    5·2 answers
  • In dynamics, the friction force acting on a moving object is always a) in the same direction of its motion b) a kinetic friction
    15·1 answer
  • One who is trained in math, science and physics in order to work in a branch of engineering
    7·2 answers
  • For the system in problem 4, suppose a main memory access requires 30ns, the page fault rate is .01%, it costs 12ms to access a
    14·1 answer
  • Everfi futuresmart module 6 retirement pie chart
    5·2 answers
  • Please help! timed test. This about electrical control. Please be serious.
    15·1 answer
  • what do you expect the future trends of an operating system in terms of (a) cost (b) size (c) multitasking (d) portability (e) s
    12·1 answer
  • GOOD AFTERNOON GUYSS!! ​
    15·2 answers
  • 12. What procedure should you follow when taking measurements?
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!