The IPA transcription of quel is [kɛl]. The consonant k in French is unaspirated and unvoiced.

This is in opposition to g as in goût [gu], which is unaspirated and voiced.

I am guessing from your name that your mother tongue is Chinese, but if I am wrong please correct me.

In Putonghua, the opposition between the syllables ka [kʰa] (unvoiced and aspirated) and ga [ka] (unvoiced and unaspirated) is one of aspiration and not voicing. The difficulty here is that Putonghua ga is variably realized with some voicing as [ga] (see here).

In summary, French k is like an unvoiced realization of Pinyin g, while French g is like a voiced realization of Pinyin g. To a speaker of Putonghua, French k and g both sound like Pinyin g.