Find all School-related info fast with the new School-Specific MBA Forum

It is currently 30 Sep 2014, 01:57

Close

GMAT Club Daily Prep

Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

A gasoline engine in a factory is fitted with an automatic

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Senior Manager
Senior Manager
User avatar
Joined: 19 Feb 2004
Posts: 415
Location: Lungi
Followers: 1

Kudos [?]: 1 [0], given: 0

A gasoline engine in a factory is fitted with an automatic [#permalink] New post 01 Apr 2004, 05:57
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

100% (02:38) correct 0% (00:00) wrong based on 1 sessions
3. A gasoline engine in a factory is fitted with an automatic control
mechanism. Whenever the temperature of the engine's exhaust
increases, the flow of air to the engine is boosted . When more air
is introduced into the engine , fuel flow is increased into the
engine, fuel flow is increased to keep the air / fuel mixture is
constant. As more air and fuel are combusted , the engine's speed and
exhaust temperature both increase.

Which of the following can we expect from an engine with this control
mechanism?

a. The engine will oscillate between medium and low speeds.
b. The engine will not run continuously; the control mechanism will
automatically bring the engine to a stop.
c. The engine will accelerate to its maximum and possible speed and
stay there.
d. The engine will overheat within an hour of the engine's ignition.
e. The engine will oscillate between high and medium speeds.
Director
Director
avatar
Joined: 03 Jul 2003
Posts: 656
Followers: 2

Kudos [?]: 14 [0], given: 0

 [#permalink] New post 01 Apr 2004, 08:50
This is a tough one!

I would go with D.
C is close but it seems out of scope of this topic!
GMAT Club Legend
GMAT Club Legend
avatar
Joined: 15 Dec 2003
Posts: 4318
Followers: 22

Kudos [?]: 164 [0], given: 0

 [#permalink] New post 01 Apr 2004, 08:53
kpadma wrote:
This is a tough one!

I would go with D.
C is close but it seems out of scope of this topic!

There is no way to infer that the engine will overheat in exactly 1 hour. It could take 5 min. as it could take 3 days. C is better because according to the process, the temp. will keep increasing and so will the machine's speed. Obviously, it will eventually reach a maximum speed; it will then no longer be able to increase its speed anymore and it will just stay there
_________________

Best Regards,

Paul

SVP
SVP
User avatar
Joined: 30 Oct 2003
Posts: 1798
Location: NewJersey USA
Followers: 4

Kudos [?]: 35 [0], given: 0

 [#permalink] New post 01 Apr 2004, 18:26
It is not very clear where the feedback mechanism is here. Only reasonable thing to be assumed here is that speed reaches its maximum limit and engine temperature can keep on increasing because flow is limited and flue mixture is limited. There is nothing mentioned about controlling temperature

Though D looks fine, I am still ticked off about the one hour time limit.

Since the argument is talking about the temperature of the exhaust and not the engine's it is safe to expect C will occur because more the fuel more the temperature. Since speed is limited and so is the air flow which in turn causes limited fluel flow. Once flue is limited the temperature of exhaust cannot increase.
Senior Manager
Senior Manager
User avatar
Joined: 19 Feb 2004
Posts: 415
Location: Lungi
Followers: 1

Kudos [?]: 1 [0], given: 0

 [#permalink] New post 02 Apr 2004, 00:03
Oh Yeah is C.

Choice C is correct. The control system described in the passage is
known as a feedback loop; as increase in the exhaust temperature
results in an increase in fuel flow, which results in an increase in
exhaust temperature, which results in yet another increase in airflow
and so on . Under these conditions , we could only expect the engine
to continue to run faster and faster until it cannot increase the
airflow or the fuel flow, or both. Since it is obviously impossible
to infinetly increase in the air or fuel flows, the engine will reach
some unknown maximum speed, and maintain that speed as in choice C.
Choices A , B and E describe results which might be obtained by some
other engine control system, but not by this feedback loop. It is not
necessarily true that the engine will overheat as in choice D.
  [#permalink] 02 Apr 2004, 00:03
    Similar topics Author Replies Last post
Similar
Topics:
Gasoline-powered boat engines manufactured in the North mymba99 6 29 May 2008, 16:05
Diesel engines burn as much as 30% less fuel than gasoline marcodonzelli 3 12 Feb 2008, 21:40
Diesel engines burn as much as 30% less fuel than gasoline EconGirl 10 23 Sep 2006, 12:36
Gasoline-powered boat engines manufactured in the North HIMALAYA 6 28 Dec 2005, 20:02
Gasoline-powered boat engines manufactured in the a North wild_desperado 7 16 Jun 2005, 04:04
Display posts from previous: Sort by

A gasoline engine in a factory is fitted with an automatic

  Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Privacy Policy| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group and phpBB SEO

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.