Machine Design - Study Mode

[#136] In composite or reverse laid ropes
Correct Answer

(C) Wires in two adjacent strands are twisted in opposite direction

[#137] In the assembly of pulley, key and shaft
Correct Answer

(B) Key is made the weakest

[#138] The groove angle of pulleys for V-belt is
Correct Answer

(A) 34° to 36°

[#139] When the speed of belt increases,
Correct Answer

(D) The power transmitted will increase

Explanation

Solution: When the speed of the belt increases The power transmitted by a belt drive is directly proportional to the product of the belt tension and the belt speed Power (P) = (T₁ - T₂) × v , where T₁ is the tension in the tight side, T₂ is the tension in the slack side, and v is the belt speed As the belt speed increases, assuming the tensions remain constant, the power transmitted also increases However, there's a practical limit to this, because at very high speeds, centrifugal force increases and reduces the effective friction and tension difference But initially, with an increase in speed, the power transmitted increases

[#140] For unequal width of butt straps, the thicknesses of butt straps are
Correct Answer

(B) 0.75 t for wide strap on the inside and 0.625 t for narrow strap on the outside