Is the H silent in WHIP?

Yes, strictly speaking, the WH in whip should be pronounced as in what, where, when. Most Americans don’t go to the trouble to overpronounce the WH sound, and to most Americans, it sounds affected.

What is the meaning of strict?

Strict describes someone who sticks to a particular set of rules. If your math teacher is strict, it means that she expects her rules to be followed to the letter. The adjective strict always has to do with rules. Your strict parents enforced rules and expected you to obey them.

Is the T silent in exactly?

In practice, yes it is virtually silent unless one makes a special effort to pronounce it. When we have a consonant cluster here /ktl/ one sound is often not heard. The linguistice term for it is “dissimilation”.