Which one of the following polar diagrams corresponds to a lag network?

The transistors used in a portion of the TTL gate shown in figure have β=100. the base-emitter voltage of is 0.7V for a transistor in active region and 0.75V for a transistor in saturation . If the sink current I=1mA and the output is at logic 0, then the current $${I_R}$$ I will be equal to

Both transistors T1 and T2 in figure have a threshold voltage of 1 Volt. The device parameters $${K_1}$$ and $${K_2}$$ of $${T_1}$$ and $${T_2}$$ are, respectively, 36 µA/ $${V^2}$$ and and 9$$9\,A/{V^2}$$. The output voltage $${V_0}$$ IS

The present output Q_n of an edge triggered JK flip-flop is logic 0. If J=1, then Q_n+1