Answer Happy

Question 1 [10 Marks] a) To design a circuit, three picofarad capacitors namely C₁, C₂ and C3 labelled as 160pF, 180pF and 200pF are used respectively. The following information are given: ● The three capacitors, C₁, C2 and C3, were measured. We found that the measured values of the three capacitors are C₁=157pF, C2= 178pF and C3= 202pF. Based on the data sheets of the three capacitors, C₁, C2 and C3, we found that the tolerances of the three capacitors are the same which are 10%. ● i) Determine the error of each capacitor compared to the labelled value. If the three capacitors are connected in parallel, what is the error of the total capacitance? (7pF) [3 marks] ii) What is the uncertainty of the total capacitance when the three capacitors are connected in parallel? (31.30pF) [4 marks] [Hint: Total capacitance C₁-C₁+C2+C3] b) [Part b is not related to Part a] A valve illustrated in Figure 1b moves from closed to maximum open with ten turns of a valve shaft. The valve shaft is driven through a 20: 1 reducer from a stepping motor of 5.0° per step. In a process, a minimum time of 10 seconds is required for the valve to move from closed to maximum open. Find the minimum input pulse rate to the motor in order to satisfy the requirement of the process. (1440 pulse / s) [3 marks] 20:1 reducer со Motor Stepping Shaft Motor Valve Shaft Valve Figure 1b