5. The electrical signal for control devices: 6. The pneumatic signal for control device: 7. A normally closed solenoid valve: a. allows fluid to flow until power is applied to the process b. prevent fluid flow flowing until power is applied to the process c. prevent fluid from flowing until power is disconnected to the process d. prevent fluid to flow all the time 8. the most suitable mode of the controller for very sensitive temperature control in a reactor. The temperature has however a continues noise. a. P- only b. PID c. PD d. PI 9. the most suitable mode of the controller for the level control in a storage tank is: a. on-off controller b. PID c. PD d. P-only 10. The basic for the selection of the action of the control valves is: a. Speed of the response b. Emergency and or instrument failures c. Valve characteristics d. Size of the control valve 11. In the P-only mode of the controller can be decreases the offset by: a. increase Ks b. decrease Kr c. no effeet with K, d. none of above 12. Cancelled the disturbance variable from the process, the kind of controller in closed controller: a. Feedback control system b. Feedforword control system c. Cascade control system d. Open - loop control system 13. The function of a transducer is to A.modify the input signal. B.amplify the input signal. C.convert the primary signal into a more useful quantity, usually an electric impulse