Machine Design

1

 

For a bevel gear having the pitch angle `theta` , the ratio of formative number of teeth (TE) to actual number of teeth (T) is

A. `1//sin theta`
B. `1//cos theta`
C. `1//tan theta`
D. `sin theta cos theta`

2

When a shaft is subjected to combined twisting moment (T) and bending moment (M), then the equivalent bending moment is equal to

A. `1/2 sqrt(M^2 + T^2)`
B. ` sqrt(M^2 + T^2)`
C. `1/2 (M + sqrt(M^2 + T^2)`
D. `M + sqrt(M^2 + T^2)`

3
If P1 is the initial tension due to tightening up the bolt and P2 is the external load on the bolt, then the resultant load (P) on a bolt may be obtained by using the relation (where a = Ratio of elasticity of connected parts to the elasticity of bolt)
A. `P = P_1 + P_2`
B. `P = P_1 - P_2`
C. `P = P_1 + ((1 + a)/(a) ) P_2`
D. `P = P_1 + ((a)/(1 + a)) P_2`

4
The notch sensitivity q is expressed in terms of fatigue stress concentration factor Kf and theoretical stress concentration factor Kt, as
A. `(k_f + 1)/(k_t + 1)`
B. `(k_f - 1)/(k_t - 1)`
C. `(k_t + 1)/(k_f+ 1)`
D. `(k_t -1)/(k_f - 1)`

5

According to maximum shear stress theory, the maximum shear stress in the shaft is 

A. `1/2 sqrt(sigma ^2 +4 tau^2)`
B. `sqrt(sigma ^2 +4 tau^2)`
C. `1/2 [ sigma + sqrt(sigma ^2 +4 tau^2)]`
D. `sigma + sqrt(sigma ^2 +4 tau^2)`