Machine Design (2171909) MCQs

MCQs of Design of Cranes

Showing 21 to 30 out of 36 Questions
21.

In Lang lay ropes, both inner and outer wires are bent on the same arc of the radius.

(a)

True

(b)

False

Answer:

Option (b)

22.

Lang lay ropes offer more resistance to __________.

(a)

fatigue failure

(b)

abrasive failure

(c)

fatigue failure and abrasive failure

(d)

none of the mentioned

Answer:

Option (c)

23.

The wire ropes make contact at

(a)

bottom of the groove of the pulley

(b)

sides of the groove of the pulley

(c)

sides and bottom of groove of the pulley

(d)

anywhere in the groove of the pulley

Answer:

Option (a)

24.

The material commonly used for crane hooks is

(a)

cast iron

(b)

wrought iron

(c)

mild steel

(d)

aluminium

Answer:

Option (b)

25.

________ is generated in the wire rope due to the axial load lifted and the weight of the rope.

(a)

Direct stress

(b)

Bending stress

(c)

Shear stress

(d)

Accelerating stress

Answer:

Option (a)

26.

When there is no slackness in the wire rope, the Impact load during starting is 

(a)

(P + p)

(b)

2(P + p)

(c)

3(P + p)

(d)

4(P + p)

Answer:

Option (b)

27.

The wire rope is subjected to

(a)

tensile stress

(b)

bending stress

(c)

both bending and tensile stress

(d)

none of the listed

Answer:

Option (c)

28.

In the design of wire ropes, bending stress is converted into an equivalent bending load which is given by [d= diameter of individual wire and D= the diameter of sheave].

(a)

AEd/D

(b)

2AEd/D

(c)

AEd/2D

(d)

AEd/3D

Answer:

Option (a)

29.

An elevator is assembled to raise equipment to a height of 22m. It is estimated that the maximum weight of the material to be raised is 4.9kN. It is observed acceleration in such cases is 1.2m/s².10mm diameter wire ropes with fiber core are used. The tensile designation of the wire is 1500. The number of wire ropes can be taken 2. Calculate the weight of material raised by each rope.

(a)

1225N

(b)

2450N

(c)

4900N

(d)

9800N

Answer:

Option (b)

30.

An elevator is assembled to raise equipment to a height of 22m. It is estimated that the maximum weight of the material to be raised is 4.9kN. It is observed acceleration in such cases is 1.2m/s².10mm diameter wire ropes with fiber core are used. The tensile designation of the wire is 1500. The number of rope wires is assumed to be 2. Calculate the weight of wire if the weight of 50m wire is 18kg.

(a)

19.36N

(b)

90.25N

(c)

77.70N

(d)

56.66N

Answer:

Option (c)

Showing 21 to 30 out of 36 Questions