In load flow studies of a power system, the quantities specified at a voltage-controlled bus are ____________and___________

The impulse response of a network is $$h\left( t \right) = 1$$ for $$0 \le t < 1$$ and zero otherwise. Sketch the impulse response of two such networks in cascade, neglecting loading effects.

Match the following transfer functions and impulse responses

Transfer functions
$$\eqalign{ & \left( a \right)\,\,\,\,\,\,\,\,{1 \over {s\left( {s + 1} \right)}} \cr & \left( b \right)\,\,\,\,\,\,\,\,{1 \over {{{\left( {s + 1} \right)}^2}}} \cr & \left( c \right)\,\,\,\,\,\,\,\,{1 \over {s\left( {s + 1} \right) + 1}} \cr & \left( d \right)\,\,\,\,\,\,\,\,{1 \over {{s^2} + 1}} \cr} $$

Impulse Responses