Day 4 || Validation rules in salesforce || Salesforce Admin Interview preparation series

This is the day 4 of our interview preparation series where we have discussed validation rules.
These are the questions we have discussed along with the practical demo and practice -
What is Cross object Validation rule?
Can we bypass validation rule for a user? or for an object?
Can we bypass validation rule for data loader?
Can we prevent deletion via validation rule?
Can we run the validation rule just for the Insert of the record?
Can we make a field required by Validation rules? what are other ways to make a field required?
Can we prevent deletion of the child record from parent record via validation rule?
If there is a validation rule which check that the amount value on opportunity should not be greater than 50 and if there is a workflow rule which updates it to 100, what will happen if we create a record on opportunity?
Validation rule: If validation contains formula field, which in turn invokes another formula. How much deep we can go with formula fields