Using “请稍等一下”may be more suitable. What’s more, you can just say ’稍等’,’等一下’or ‘等会’ in informal situation.

no，you can say:请稍等一下/请等一下/请稍候。

In fact, there are lots of way to say "please wait a sec?" If you use 稍候, it is usually a bit formal. You can still used in daily conversation though. One of the common situation is in restaurant or on the phone when you want the customer to hold on a sec. Other ways of saying this include: 請稍等一下 請稍等 稍等一下/稍等一會 等等 等一等 等一下 等我一下 Hope it helps. Good luck with the learning.

it can be informal，imagining that you are very busy at work，but someone who might be ur colleague phones you for another stuff，but u dont want to be disturbed.then u can respond he or she like 请稍等一下，and you put 请 before another words just being polite.also，if u want to say that more informal，just say 等一下，and this can be translated to hold on，seems more natural

it can be informal，imagining that you are very busy at work，but someone who might be ur colleague phones you for another stuff，but u dont want to be disturbed.then u can respond he or she like 请稍等一下，and you put 请 before another words just being polite.also，if u want to say that more informal，just say 等一下，and this can be translated to hold on，seems more natural