Alphabet ক

IPA /k/ ISO /k/ U+8965

Try to read the word King.

Let's replace the K with ক. কING.

Can you read it? It would be pronounced King exactly. Basically there is no difference in their pronunciation. ক is pronounced exactly like K. I mean, ক is the Bengali form of K or in other words K is the English form of ক.

The difference is that ক has an inherent /ɔ/ associated with it by default which K does not.

Let's look at some more examples.

KELVIN > কELVIN KITE > কITE KASHMIR > কASHMIR

N.B.

A consonant in Bengali gives only one sound, i.e. there can be more than one pronunciation of C in English, which is not the case in Bengali.  In English words like Cat, Queen, Queue, Capseller, etc., C or Q will be considered as ক in Bengali because they actually sound K.

কলম

Allies of ক (as sound)

Alphabet খ

IPA /k/ ISO /kha/ U+8965

খ is the twin of ক (K) with a aspirated feature. It's kinda identical to Scottish or French ch in Munich.