Test: Torsion - 1 - Mechanical Engineering MCQ

The diameter of a shaft is increased from 30 mm to 60 mm, all other conditions remaining unchanged. How many times is its torque carrying capacity increased?

The magnitude of stress induced in a shaft due to applied torque varies

Maximum shear stress developed on the surface of a solid circular shaft under pure torsion is 240 MPa. If the shaft diameter is doubled then the maximum shear stress developed corresponding to the same torque will be:

A torque T is applied at the free end of a stopped rod of circular cross-sections as shown in the figure. The shear modulus of the material of the rod is G. The expression for d to produce an angular twist θ at the free end is

Maximum shear stress developed on the surface of a solid circular shaft under pure torsion is 240 MPa. If the shaft diameter is doubled, then what is the maximum shear stress developed corresponding to the same torque?

The magnitude of stress induced in a shaft due to applied torque varies

Assertion (A): In a composite shaft having two concentric shafts of different materials, the torque shared by each shaft is directly proportional to its polar moment of inertia.

Reason (R): In a composite shaft having concentric shafts of different materials, the angle of twist for each shaft depends upon its polar moment of inertia.

One-half length of 50 mm diameter steel rod is solid while the remaining half is hollow having a bore of 25 mm. The rod is subjected to equal and opposite torque at its ends. If the maximum shear stress in solid portion is τ or, the maximum shear stress in the hollow portion is:

A shaft can safely transmit 90 kW while rotating at a given speed. If this shaft is replaced by a shaft of diameter double of the previous one and rotated at half the speed of the previous, the power that can be transmitted by the new shaft is:

A shaft is subjected to fluctuating loads for which the normal torque (T) and bending moment (M) are 1000 N-m and 500 N-m respectively. If the combined shock and fatigue factor for bending is 1.5 and combined shock and fatigue factor for torsion is 2, then the equivalent twisting moment for the shaft is:

A shaft is subjected to simultaneous action of a torque T, bending moment M and an axial thrust F. Which one of the following statements is correct for this situation?

A circular shaft is subjected to the combined action of bending, twisting and direct axial loading. The maximum bending stress σ, maximum shearing force √3σ and a uniform axial stress σ(compressive) are produced. The maximum compressive normal stress produced in the shaft will be:

A hollow shaft of same cross-section area as solid shaft transmits

A solid shaft of diameter 100 mm, length 1000 mm is subjected to a twisting moment 'T‟ The maximum shear stress developed in the shaft is 60 N/mm2. A hole of 50 mm diameter is now drilled throughout the length of the shaft. To develop a maximum shear stress of 60 N/mm2 in the hollow shaft, the torque 'T‟ must be reduced by: 

For the two shafts connected in parallel, find which statement is true? 

Assertion (A): In theory of torsion, shearing strains increase radically away from the longitudinal axis of the bar.

Reason (R): Plane transverse sections before loading remain plane after the torque is applied. 

A shaft is subjected to a bending moment M = 400 N.m alld torque T = 300 N.m The equivalent bending moment is: