Does cloud bill even after azure function is disable. Bill plan B1

No, Microsoft doesnt price you for the disabled functions. You can use the pricing calculator as well the below link to check the pricing factors

https://azure.microsoft.com/en-in/pricing/details/functions/ 

Yes, I think there will be minor charge for using App Service Plan even the resources are stopped. 

Disabling an Azure Function with the B1 billing plan will halt its execution and prevent associated costs while it's inactive.

Microsoft does not charge for a disabled function, as billing is based on resource consumption when the function is active and processing requests. However, other resources linked to the function, like storage, may continue to incur costs even when the function is disabled.

To optimize costs further, consider scaling the function app appropriately and regularly monitoring resource usage. Always review Azure billing details and consult official documentation or support for precise billing information.

No charges if it is disabled. But if your function has a dependency on other resources like storage that dependency cost may apply.

No, Microsoft won't charge anything if azure function is in disable state. Although the database which is attached to the function will be charged.

As azure function is paas service the pricing of function is based on no. of executions. For more details go to the following url  :- https://azure.microsoft.com/en-in/pricing/details/functions/