It is currently 20 Sep 2017, 20:30

### 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

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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# A new silencing device for domestic appliances operates by

 new topic post reply Question banks Downloads My Bookmarks Reviews Important topics
Author Message
VP
Joined: 26 Apr 2004
Posts: 1209

Kudos [?]: 795 [0], given: 0

Location: Taiwan
A new silencing device for domestic appliances operates by [#permalink]

### Show Tags

10 Mar 2005, 19:43
00:00

Difficulty:

(N/A)

Question Stats:

100% (00:00) correct 0% (00:00) wrong based on 0 sessions

### HideShow timer Statistics

A new silencing device for domestic appliances operates by producing sound waves that cancel out the sound waves produced by the appliance. The device, unlike conventional silencers, actively eliminates the noise the appliance makes, and for that reason vacuum cleaners designed to incorporate the new device will operate with much lower electricity consumption than conventional vacuum cleaners.

Which one of the following, if true, most helps to explain why the new silencing device will make lower electricity consumption possible?

(A) Designers of vacuum cleaner motors typically have to compromise the motorsâ€™ efficiency in order to reduce noise production.

(B) The device runs on electricity drawn from the applianceâ€™s main power supply.

(C) Conventional vacuum cleaners often use spinning brushes to loosen dirt in addition to using suction to remove dirt.

(D) Governmental standards for such domestic appliances as vacuum cleaners allow higher electricity consumption when vacuum cleaners are quieter.

(E) The need to incorporate silencers in conventional vacuum cleaners makes them heavier and less mobile than they might otherwise be.

Kudos [?]: 795 [0], given: 0

VP
Joined: 25 Nov 2004
Posts: 1482

Kudos [?]: 121 [0], given: 0

Re: CR020317--silencing device [#permalink]

### Show Tags

10 Mar 2005, 20:50
I am also tempted with B but choose A.

(A) Designers of vacuum cleaner motors typically have to compromise the motorsâ€™ efficiency in order to reduce noise production.

Kudos [?]: 121 [0], given: 0

Director
Joined: 01 Feb 2003
Posts: 844

Kudos [?]: 121 [0], given: 0

### Show Tags

10 Mar 2005, 23:49
A should be it...(Sorry for not giving the explanations right away!)

Kudos [?]: 121 [0], given: 0

GMAT Club Legend
Joined: 07 Jul 2004
Posts: 5039

Kudos [?]: 424 [0], given: 0

Location: Singapore

### Show Tags

11 Mar 2005, 00:37
The conclusion here is 'vacuum cleaners that incorporate the new silencing device will operate with much lower electricity comsumption than conventional vacuum cleaners'

The premises:
New silencing device for domestic appliances operates by producing sound waves that cancel out the sound waves produced by the appliance
Device actively eliminates the noise the appliance makes.

From the premise to the conclusion, we're missing out a big chunk of assumption. We need something that tells us how the device reduces lower electricity consumption.

(A) Designers of vacuum cleaner motors typically have to compromise the motorsâ€™ efficiency in order to reduce noise production.
- If the vacuum cleaner is not efficient, then you will need to spend more time just vacuuming your house (because it's inefficient and takes a long time to finsih cleaning whatever its suppose to clean). Indirectly, you will be leaving your vacuum cleaner on for a longer period, and thus draw more electricity.

(B) The device runs on electricity drawn from the applianceâ€™s main power supply.
- Not important.

(C) Conventional vacuum cleaners often use spinning brushes to loosen dirt in addition to using suction to remove dirt.
- Doesn't tell us a thing.

(D) Governmental standards for such domestic appliances as vacuum cleaners allow higher electricity consumption when vacuum cleaners are quieter.
- Not important.

(E) The need to incorporate silencers in conventional vacuum cleaners makes them heavier and less mobile than they might otherwise be.
- Only makes them difficult to carry around. Doesn't tell us how it reduces electricity consumption.

A it is.

Kudos [?]: 424 [0], given: 0

SVP
Joined: 30 Oct 2003
Posts: 1788

Kudos [?]: 108 [0], given: 0

Location: NewJersey USA

### Show Tags

11 Mar 2005, 10:23
damn I was debating between (A) and (B). I think this is a poor quality CR.
I chose (A) in doubt.

Efficiency of motor = power output (PO) /power input (PI).

If this ratior is lower it may mean that
Keep PI constant but reduce PO drastically
or
Increase PO but increase PI even more.

Kudos [?]: 108 [0], given: 0

Senior Manager
Joined: 07 Nov 2004
Posts: 453

Kudos [?]: 121 [0], given: 0

### Show Tags

11 Mar 2005, 11:05
My reasoning is smiple, compromising efficency means using more electric. so A is my choice

Kudos [?]: 121 [0], given: 0

VP
Joined: 26 Apr 2004
Posts: 1209

Kudos [?]: 795 [0], given: 0

Location: Taiwan

### Show Tags

11 Mar 2005, 20:46
ywilfred wrote:
The conclusion here is 'vacuum cleaners that incorporate the new silencing device will operate with much lower electricity comsumption than conventional vacuum cleaners'

The premises:
New silencing device for domestic appliances operates by producing sound waves that cancel out the sound waves produced by the appliance
Device actively eliminates the noise the appliance makes.

From the premise to the conclusion, we're missing out a big chunk of assumption. We need something that tells us how the device reduces lower electricity consumption.

(A) Designers of vacuum cleaner motors typically have to compromise the motorsâ€™ efficiency in order to reduce noise production.
- If the vacuum cleaner is not efficient, then you will need to spend more time just vacuuming your house (because it's inefficient and takes a long time to finsih cleaning whatever its suppose to clean). Indirectly, you will be leaving your vacuum cleaner on for a longer period, and thus draw more electricity.

(B) The device runs on electricity drawn from the applianceâ€™s main power supply.
- Not important.

(C) Conventional vacuum cleaners often use spinning brushes to loosen dirt in addition to using suction to remove dirt.
- Doesn't tell us a thing.

(D) Governmental standards for such domestic appliances as vacuum cleaners allow higher electricity consumption when vacuum cleaners are quieter.
- Not important.

(E) The need to incorporate silencers in conventional vacuum cleaners makes them heavier and less mobile than they might otherwise be.
- Only makes them difficult to carry around. Doesn't tell us how it reduces electricity consumption.

A it is.

Thanks OA is A

more efficient means less power consumption and vice versa?.
oh, so deep gap.

Kudos [?]: 795 [0], given: 0

11 Mar 2005, 20:46
Similar topics Replies Last post
Similar
Topics:
Many TV viewers own devices that can be set up to record 11 13 Jun 2009, 23:37
Many TV viewers own devices that can be set up to record 9 30 Jun 2008, 22:50
Krenland s steelmakers are losing domestic sales because of 0 03 Nov 2015, 05:01
The peculiar evil of silencing the expression of an opinion 2 23 Jun 2009, 10:40
The peculiar evil of silencing the expression of an opinion 6 09 Jun 2008, 16:26
Display posts from previous: Sort by

# A new silencing device for domestic appliances operates by

 new topic post reply Question banks Downloads My Bookmarks Reviews Important topics

 Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne 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®.