#17 - A new silencing device for domestic appliances

[akalsi]

So I don't quite understand why the answer in this question is A. What does the motors' efficiency have to do with the lower electricity consumption? To me it just doesn't seem like having to compromise the motors' efficiency is something that is relevant to the explaining the issue in the stimulus. Is there something I'm missing here

Can you break this down for me and explain why A is right?

Thanks,
Anoop

[David Boyle]

So I don't quite understand why the answer in this question is A. What does the motors' efficiency have to do with the lower electricity consumption? To me it just doesn't seem like having to compromise the motors' efficiency is something that is relevant to the explaining the issue in the stimulus. Is there something I'm missing here

Can you break this down for me and explain why A is right?

Thanks,
Anoop

Hello,

A more inefficient motor would usually tend to use more electricity, one imagines.

David

[bricbas]

Hello,

A more inefficient motor would usually tend to use more electricity, one imagines.

David

This is the very reason why I can't see why A is right. The only thing that A says is that manufacturers trying to make the motor quieter have to compromise efficiency, so if they use the device to make the motor more quiet, it isn't any less likely that they will have to compromise efficiency. I feel like they are skirting the surface of a strengthen answer without doing just that strengthening the argument.

[David Boyle]

Hello,

A more inefficient motor would usually tend to use more electricity, one imagines.

David

This is the very reason why I can't see why A is right. The only thing that A says is that manufacturers trying to make the motor quieter have to compromise efficiency, so if they use the device to make the motor more quiet, it isn't any less likely that they will have to compromise efficiency. I feel like they are skirting the surface of a strengthen answer without doing just that strengthening the argument.

Hello bricbas,

Hmm.....maybe the silencing device itself will have to consume power, maybe. Still, A does give a good reason why the main motor itself may have to consume less power; because it does not have to make less noise, since the silencer is destroying the noise instead.

Hope this helps,
David

[simonsap]

Easy peasy.

Stimulus: an additional device lowers noise of given appliance but also somehow reduces electricity consumption.

Paradox? Presumably adding a device to the appliance would make it consume more electricity.

Answer A tells us that -- prior to the addition of this device -- to achieve a quieter appliance, engineers had to make the motor more inefficient. By adding the appliance, they can stop worrying about how much noise it makes (BECAUSE the noise reducing device will now take care of that) and focus on making it more efficient. When it is more efficient, it uses less electricity. Even though the silencing devices consumes X additional electricity, because the motor was made more efficient, the SUM electricity consumption of the appliance is reduced.