50. Maximum permissible slenderness ratio of compression members which carry dead and superimposed load, is

A.350

B.250

C.180

D.80

51. For determination of allowable stress in axial compression, Indian Standard Institution has adopted

A. Euler's formula

B. Rankine formula

C. Engesser formula

D. Secant formula

52. The slenderness ratio of a column is zero when its length

A. is zero

B. is equal to its radius of gyration

C. is supported on all sides throughout its length

D. is between the points of zero moments.

53. The most economical section for a column, is

A. rectangular

B. solid round

C. flat strip

D. tubular section

54. A compression member consisting of angle sections may be a

A. continuous member

B. discontinuous single angle strut

C. discontinuous double angle strut

D. all the above.

55. The effective length of a double angle strut with angles placed back to back and connected to both the sides of a gusset plate, by not less than two rivets, is

A. 0.5 L

B. 0.67 L

C. 0.85 L

D. L

56. Allowable working stress corresponding to the slenderness ratio of double angles placed back to back and connected to one side of a gusset plate, is reduced to

A.50%

B.60%

C.70%

D.80%

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