Machine Design - Study Mode
[#421] Two closely coiled helical springs with stiffness k 1 and k 2 respectively are connected in series. The stiffness of an equivalent spring is given by
Correct Answer
(A) $$frac{{{{ ext{k}}_1}{{ ext{k}}_2}}}{{{{ ext{k}}_1} + {{ ext{k}}_2}}}$$
[#422] For same pulley diameters, center distance, belt speed and belt and pulley materials,
Correct Answer
(B) Crossed belt drive transmits more power than open belt drive
[#423] Two shafts will have equal strength, if
Correct Answer
(D) Twisting moment of both the shafts is same
Explanation
Solution: Two shafts will have equal strength if the twisting moment of both the shafts is the same. Twisting moment determines the ability of a shaft to resist the applied torque without failure. It is given by the formula: T = τ × Z p Where: T = Twisting moment τ = Shear stress Z p = Polar section modulus Equal twisting moments imply that the shafts will experience the same level of stress and deformation under the applied torque, ensuring they have equal strength. Therefore, Option D is the correct answer.
[#424] The draw of cotter need not exceed
Correct Answer
(A) 3 mm
[#425] For a bevel gear having the pitch angle $$ heta $$, the ratio of formative number of teeth (TE) to actual number of teeth (T) is
Correct Answer
(B) $$frac{1}{{cos heta }}$$