Question

He is very pleased because he has ------ [pass] the exam

Answer 1

he is very pleased because he has passed the exam.

Answer 2

This blank can be filled with the word 'passed'

So, correct sentence will be:-

He is very pleased because he has passed the exam.

Passed is the past form of pass. This form is used when sentence is in past or present perfect tense.

We can detect whether the sentence is in present, past or future be looking the sentence structure.

Here the second sentence is in present perfect tense. So V3 form will use here.

Hence, past form of verb will be used that is passed.