Ask Science

8463 readers

1 users here now

Ask a science question, get a science answer.

Community Rules

Rule 1: Be respectful and inclusive.

Treat others with respect, and maintain a positive atmosphere.

Rule 2: No harassment, hate speech, bigotry, or trolling.

Avoid any form of harassment, hate speech, bigotry, or offensive behavior.

Rule 3: Engage in constructive discussions.

Contribute to meaningful and constructive discussions that enhance scientific understanding.

Rule 4: No AI-generated answers.

Strictly prohibit the use of AI-generated answers. Providing answers generated by AI systems is not allowed and may result in a ban.

Rule 5: Follow guidelines and moderators' instructions.

Adhere to community guidelines and comply with instructions given by moderators.

Rule 6: Use appropriate language and tone.

Communicate using suitable language and maintain a professional and respectful tone.

Rule 7: Report violations.

Report any violations of the community rules to the moderators for appropriate action.

Rule 8: Foster a continuous learning environment.

Encourage a continuous learning environment where members can share knowledge and engage in scientific discussions.

Rule 9: Source required for answers.

Provide credible sources for answers. Failure to include a source may result in the removal of the answer to ensure information reliability.

By adhering to these rules, we create a welcoming and informative environment where science-related questions receive accurate and credible answers. Thank you for your cooperation in making the Ask Science community a valuable resource for scientific knowledge.

We retain the discretion to modify the rules as we deem necessary.

founded 1 year ago

MODERATORS

[email protected]

Why do many microwave ovens hum in an interval of a minor 7th? (lemmy.wtf)

submitted 9 months ago* (last edited 9 months ago) by [email protected] to c/[email protected]

43 comments fedilink hide all child comments

Something that I've noticed across most of the microwave ovens that I've used is that when they hum while cooking food, I can pick out 2 distinct tones. One of them is pretty clearly ~~60~~ 120 hz, the 2nd harmonic of the AC power frequency. The other is consistently a minor 7th above that (which would be somewhere around ~~106-108~~ 212-214 hz depending on the exact ratio). What causes this 2nd frequency to be produced?

Edit: after checking against a tone generator, the low frequency is actually 120 hz, double the grid frequency. The question is still the same, just an octave higher.

you are viewing a single comment's thread
view the rest of the comments

[–] [email protected] 5 points 9 months ago* (last edited 9 months ago) (2 children)

Mashed potatoes :

Dice small, 10-15min

Rice:

1,5dl water to 1dl rice, 10-12min

I could go on. It's a big water heater

[–] [email protected] 3 points 9 months ago (1 children)

Why have I not been microwaving rice? Does this affect the texture at all?

[–] [email protected] 1 points 9 months ago (1 children)

Only if you don't turn down the power, you want full effect to get in to temp and then turn it down to keep temperature steady

[–] [email protected] 1 points 9 months ago (1 children)

So, not what you said, then

[–] [email protected] 1 points 9 months ago

I don't think I specified, but much like cooking rice on a stove top you won't run it at the same temperature. The microwave will use less energy than a traditional stove top, not sure about induction ones. And after learning to boil things with it, I do it all the time.

Just get it to boiling then 450 then if needed 300

[–] [email protected] 1 points 9 months ago* (last edited 9 months ago)

I've never seen someone use Deciliters before! Love it. Disclaimer: I live in either the USA, Myanmar, or Liberia.