現金 and 小銭: cash including banknotes and small change
Distinguish cash from coins or small amounts of money, reading situations with cash but no small change and the separate meaning of お釣り.
Cash includes banknotes and coins
現金, read げんきん, means cash such as banknotes and coins. 財布には現金が入っています。 says that there is cash in the wallet.
現金がある alone does not tell you how many coins or banknotes are present. Separate cash as a payment method from its particular denominations and forms.
Coins or a small amount of money
小銭, read こぜに, refers to coins or a small amount of money. 小銭を集めて、百円払いました。 says that small change was gathered to pay one hundred yen.
小銭入れ refers to a coin purse or similar holder for small change. Do not extend 小銭 to mean all money or all cash.
No small change and change returned after payment
現金はありますが、小銭がありません。 says that the speaker has cash but no small change. Banknotes may still be available, so it is not a contradiction.
お釣り is the change returned from an amount paid. 千円で払って、お釣りを受け取りました。 says that one thousand yen was paid and change received. The returned money need not consist only of coins.
Does 現金はありますが、小銭がありません。 mean the speaker has no money at all?
Show the answer and why
No. The speaker has cash but no small change and may have banknotes, for example.