operating system - Converting a Virtual Address to a Physical Address -

i doing os course in college , don't understand found in slides course:

consider vm system following page table. page size 1kb.

frame valid referenced modified

4 1 1 0

7 1 1 1

0 0 0 0

2 1 0 0

0 0 0 0

0 1 0 1

it converts following addresses physical ones: 1052, 2221, 5499.

for 2221, 2221 = 2 x 1024 + 173 , says maps page #2 -> page fault.

could please explain me why leads page fault?

entry 2 (counting 0 , up) has 0 in valid bit. that's why page fault.