1) In which of the following gates, the output is 1, if and only if at least one input is 1

2) The time required for a gate or inverter to change its state is called

3) The time required for a pulse to change from 10 to 90 percent of its maximum value is called

4) The maximum frequency at which digital data can be applied to gate is called

5) What is the minimum number of two-input NAND gates used to perform the function of two input OR gate ?