(1) The paramter M, used in the lab., represents (A) the mass of the bush (C) the mass per unit length of the shaft (B) the mass of the disk (D) the total mass of disk and bush (2) The whirling speed in rps of a long shaft having Young's modulus of elasticity, E, moment of inertia, I, span, L with a rotor of mass, M placed symmetrically on the shaft is: 0.276, EIL Mab FI (B) 1.58 ΕΙ (C) 1.103, ML (D) None (3) The shaft runs at an exceptional steadiness when the rotational speed of a shaft is: (A) between 2 critical speeds (C) well below N:1 (B) at the natural frequency (D) none of the above (4) The whirling experiment performed in the lab was conducted on a shaft of span 1 m with an assymetrically located disk with a-0.8 m and b-0.2 m. The 1" whirl speed was found to be 40 rps. If a were changed to 0.7 m, the new whirl speed No: (A) decreases (C) remains unchanged (B) increases (D) the answer depends on other parameters (5) The whirling speed of a shaft can be controlled by: (6) (A) mass of the disk (B) span of the shaft (C) diameter of the shaft (D) all of these The whirling characteristics of steel shafts with a symmetrically located disk of mass 30 g are shown in Figure 1. The shaft#1 has a flexural rigidity (EI) of: (Note: the Log function used here is the base 10 logarithm) (B) 25<El ≤35 N-m² (A) El ≤25 N-m² (C) 35 < El≤45 N-m² (D) 45 < EI N-m² For a Symmetrically Located Disk y=-1.5x+1.5 For Shaft#1 Log(Nc) Shaft #1 Shaft #2 Shaft#3 0.5 -0.2 -0.15 -0.1 -0.05 ° Log(L) Figure 1.