DME_A31
Question No : 1
A temporary elevator is assembled at the construction site to raise building materials such as cement, to a height of 30m. It is estimated that the maximum weight of the material to be raised is 15kN. It is observed that the acceleration is such applications is 2m/s2. 10mm diameter 6X19 construction – wire ropes with fibre core are used for this application. The tensile designation is 1420 and factor of safety should be 10 for preliminary calculations. i)Determine the no. of wire ropes required in this case. Neglect bending stress. [Assume Breaking load = 40kN, mass of 100m wire=34.6kg]
1
5
10
2
Question No : 2
If the wires in the strands are twisted in the same direction as the strands about core. Then it is called as
Lang Lay
Lay
Regular Lay
Irregular Lay
Question No : 3
A hand operated winch has a drum of 1200mm diameter. Suggest a suitable wire rope for handling a load of 10KN with following data and find factor of safety. Assusme 6X19 wire rope therefore Beaking load = 510d^2 Cross sectional area of the rope = 0.40d^2 Sheave dia D=30d Dia of wire dw=0.063d where d is dia of rope in mm
10
7
1
18
Question No : 4
Wire Ropes are Designated with
WiresXstrands
Strands
StrandsXWires
Wires
Question No : 5
A 6X19 flexible wire rope is used for a vertical mine hoist to lift a load of 90KN from a depth of 250m. Rope speed of 8m/sec is to be attained in 10sec. Take the factor of safety as 6. Find Bending Load and Load due to acceleration [Assume Er=84000N/mm^2, dennsity of the wire rope=7600Kg/m^3]
39137 and 5548
49807 and 7983
2137 and 354
29137 and 3548
Question No : 6
Pressure Between the wire and Sheave is
2P/d.D
P/d.D
d.D/2P
P.d/2D
Question No : 7
A simple chain No. 10B is used to transmit power from a 1400 rpm electric motor to a line shaft running at 350rpm. The number of teeth on the driving sprocket wheel are 19. Calculate Tension in the chain Assume : Ks=1.0, K1=1.0, K2=1.11, pitch(p)=15.875mm Power rating = 11.67Kw, Breaking load=22.7KN
2840
1840
840
440
Question No : 8
Velocity ratio of chain drive is the ratio of
No. of Teeth on Driven sprocket to driving sprocket
No. of Teeth on driving sprocket to Driven sprocket
1/ No. of Teeth on driving sprocket
1/No. of Teeth on Driven sprocket
Question No : 9
For 6X7 Wire rope Breaking load is
680d^2
580d^2
480d^2
380d^2
Question No : 10
6X7 Wire ropes Preferred sheave diameter is
45d
75d
15d
5d
 
Designed by
Dr.M.Raja Roy
            M.E.,Ph.D
Associate Professor
Mechanical Engg. Dept
ANITS