A unity negative feedback system has an open loop transfer function k G₂ s(s+10) for the system to have a damping ratio of 0.25 the value of k must be Select one: O O O O a. non of the choices b. 200 c. 10 d. 100 e. 400

10- A unity feedback system has open-loop transfer function G(s)=2/ (S+4), the ratio of time constants of open-loop to closed loop response will be: a- 1:1 b-2:1 c- 3:2 d-2:3 11-First column elements of the Routh's tabulation are 3, 5,-0.75, 0.5,2. It means that there: a- is one root in the left half of s-plane b- are two roots in the left half of s-plane c- are two roots in the right half of s-plane d- is one root in the right half of s-plane 12-An effect of phase-lag compensation on system performance is that: a-for a given relative stability, the velocity error constant is increased b- for a given relative stability, the velocity error constant is decreased c- the bandwidth of the system is increased d- the time response is made faster 13-The phase lead compensation is used to: a- increase rise time and decrease overshoot b- decrease both rise time and overshoot c- increase both rise time and overshoot d-decrease rise time and increase overshoot 14-When phase-lag compensation is…