Question

(7 marks) 0.07) (3 marks) Find the lot quality level that will be rejected in 85% of the time. (ii) Figure 4(b) shows the sketch diagram for an electric generator. Construct a fuhtee İor the case that the motor cannot be turned on based on the available information. The following probabilities are given Power source failure 0.010 (b) Switch I failure 0.003 Switch 2 failure -0.004 Switch 3 failure 0.002 Blown fuse-0.002 Motor out 0.030 Wire broken 0.010 All Electric Wire Power SourceSwitch 1 Motor (PS) Swl)Fuse (F) Switch 3 (Sw3) Switch 2 (Sw2) Figure 4(b) 015 Word ViewSonic

Answer 1

from the fig it is clear that the motor will not work if the power source is failed or all three switches are failed or fuse is blown out or motor out happens ...

so we can construct fault tree for motor does not turned as shown below

From the fig it is clear that the motor will not work if the power source is failed or all three switches are failed or fuse is blown out or motor out happens ... so we can construct fault tree for motor does not turned as shown below P(switch failure) = P (SWIF) * P(SWZ failure) * P(SW3 failure) = 0.003 * 0.004 * 0.002 almostequalto 0 So switch failure Can be neglected p(motor doesn't on) = 0.010 + 0 + 0.002 + 0.030 + 0.010 = 0.052 from the above one the probability of failure is mostly due to fuse hence it should be taken care

from the above one the probability of failure is mostly due to fuse hence it should be taken care