What are the characteristics of AC current?

What is Zener diode? Draw its voltage vs current characteristics in the reverse bias and indicate the breakwon voltage on the characteristics. Mention one important use of this diode.

What is the change in the collector current, in a transistor of a.c. current gain 150 for a 100muA change in its base current?

The Ac current gain of a transistor is 100. If the base current changes by 100muA . What is the charge in collector current.

What is the change in the collector current , in a transistor of a.c. current gain 150, for a 100 mu A change in base current ?

What is the change in the collector current in a transistor of a.c. current gain 150, for a 100 mu A change in the base current ?