Q$2$

$($a$)$ What is a block diagram?

$($b$)$ Simplify the block diagram shown below and obtain the closed$-$loop transfer function $Y\frac{S}{Y_{sp}}(S)=G(S)$

$($c$)$ State the two distinguishing features of a cascade control loop structure.

Q$3$

Briefly explain the following

i$.$ Process variable

ii$.$ Final control element

iii. Actuators

iv$.$ Degree of freedom