A tensile test is conducted on a mild steel bar. The following data was obtained from the test: diameter of the steel bar= 3cm, Gauge Length of the bar = 20cm, Load at Elastic limit= 250kN, Extension at a load of 150kN= 0.21 mm, Maximum Load = 380kN, Total Extension= 60mm, Diameter of the rod at failure=2.25cm, determine the percentage decrease in Area?

A. 23.25%

B. 32.75%

C. 41.75%

D. 43.75%

Detail - Percentage decrease in Area = ((Original Area - Area at failure)/(original Area)) x 100 = ((0.785 x 30 x 30 - 0.785 x 22.5 x 22.5)/(0.785 x 30 x 30)) x 100= 43.75%

A tensile test is conducted on a mild steel bar. The following data was obtained from the test: diameter of the steel bar= 3cm, Gauge Length of the bar = 20cm, Load at Elastic limit= 250kN, Extension at a load of 150kN= 0.21 mm, Maximum Load = 380kN, Total Extension= 60mm, Diameter of the rod at failure=2.25cm, determine percentage elongation?

A. 10%

B. 20%

C. 30%

D. 40%

Detail - percentage elongation = (total increase in length/ original length) x 100 % = (60/200) x 100 = 30%

A tensile test is conducted on a mild steel bar. The following data was obtained from the test: diameter of the steel bar= 3cm, Gauge Length of the bar = 20cm, Load at Elastic limit= 250kN, Extension at a load of 150kN= 0.21 mm, Maximum Load = 380kN, Total Extension= 60mm, Diameter of the rod at failure=2.25cm, determine the stress at elastic limit?

A. 3.54 x 10^5 N/sq(mm)

B. 353.68N/Sq(m)

C. 353.68GN/Sq(m)

D. 0.353 N/Sq(mm)

Detail - stress at elastic limit = load at elastic limit/area = (250x 1000)/(0.785 x 30 x 30)= 353.68N/sq(mm) = 353.68 x 10^6 N/Sq(m) =353.68 GN/Sq(m)

A tensile test is conducted on a mild steel bar. The following data was obtained from the test: diameter of the steel bar= 3cm, Gauge Length of the bar = 20cm, Load at Elastic limit= 250kN, Extension at a load of 150kN= 0.21 mm, Maximum Load = 380kN, Total Extension= 60mm, Diameter of the rod at failure=2.25cm, determine young's modulus?

A. 202 GN/sqm

B. 2.02 x 10^6 N/sq(mm)

C. 0.202 x 10^4N/sq(mm)

D. 202MN/sqm

Detail - from the data given Area of bar = 0.785 x 30 x 30 =706.5 sq(mm),now,, within elastic limit load is 150kN, stress = 150000/706.5= 212.314N/sq(mm)strain = 0.21/200 = 0.00105 young modulus = stress/strain = 212.314/0.00105 = 2.02 x 10^5 N/sq(mm) =2.02x 10^11 N/sq(m) = 202 x 10^9 N/sq(m) = 202GN/Sq(m)

consider three dimensional system subjected to stress in x, y, z directions, then total strain in x direction is?

A. =longitudinal strain in x direction - lateral strain in y direction - lateral strain in z direction

B. =longitudinal strain in x direction + lateral strain in y direction + lateral strain in z direction

C. =longitudinal strain in x direction - longitudinal strain in y direction -longitudinal strain in z direction

D. =longitudinal strain in x direction + longitudinal strain in y direction + longitudinal strain in z direction

Detail - lateral strain = - poisson ratio x longitudinal strain

Find the young Modulus of a brass rod of diameter 25 mm and of length 250mm which is subjected to a tensile load of 50kN when the extension of the rod is equal to 0.3 mm.?

A. 80526

B. 86134

C. 84925

D. 82520

Detail - stress = force/area = 50000N/0.785 x 25 x 25 = 101.91 N/sq(mm)strain = extension of rod/original length of rod = 0.3/250 = 0.0012now,modulus of elasticity = stress/strain = 101.91/0.0012 = 84925 N/sq(mm)

Find the Minimum diameter of a steel wire, which is used to raise a load of 4000 N if the stress is not exceed 95MN/sq(m)?

A. 0.732mm

B. 0.732cm

C. 0.732 m

D. 7.32 mm

Detail - Stress = 95 x 10^6 N/sq(m) = 95 N/sq(mm) = force/Area alsoArea = Force/Stress = 4000/95 =42.105 sq(mm)alsoArea = 0.785xdiameterxdiameterhencediameter = (42.105/0.7850^0.5 =(53.64)^0.5 =7.32 mm = 0.732 cm

A rod 150 cm long and of diameter 2.0 cm is subjected to an axial pull of 20kN. If the modulus of elasticity of the material of the rod is 2 x 10^5 N/Sq(mm) ; determine : the elongation in rod?

A. 0.477cm

B. 0.00477cm

C. 0.0477cm

D. 0.000477cm

Detail - elongation of rod = original length x strain, we know that original length is equal to 150cmstrain = stress/modulus of elasticity = force/ Area x modulus of elasticity = 20000/(0.785 x 20 x 20 x 200000) = 0.000318 by putting value of strain in elongation formula we getelongation of rod = strain x original length = 0.000318 x 150 = 0.0477 cm

A rod of 150cm long and of diameter 2.0 cm is subjected to an axial pullof 20kN. If the modulus of elasticity of the material of the rod is 2 x 10^5 N/sq(mm), determine strain?

A. 0.000318

B. 0.00318

C. 0.0000318

D. 0.0318

Detail - we know that, Modulus of elasticity is stress/strain,stress is equal to force/area, hence by putting value of Area = 0.785 x diameter x diameter, and force is equal to 20000 N, we get stress equal to 63.662 N/sq(mm),now, from the equation of hookes law,strain = stress/modulus of elasticity = 63.662/200000 = 0.000318

A rod 150 cm long and of diameter 2.0 cm is subjected to an axial pull of 20kN. If the modulus of elasticity of the material of the rod is 2 x 10^5 N/Sq(mm) ; determine : the stress?

A. 63.600 N/sq(mm)

B. 63.500 N/sq(mm)

C. 63.662 N/sq(mm)

D. 63.562 N/sq(mm)

Detail - Area of Rod:- (π/4)(radius^2) :- 100π sq(mm),now,Stress= Force/Area = 20000/100π = 63.662 N/sq(mm)

World of Education Global Organization,Wedugo App,gk questions,quiz questions,general knowledge questions and answers,general knowledge quiz with answers,general knowledge quiz and answers,science quiz questions and answers,free quiz questions and answers,easy quiz questions and answers,science quiz questions,free quiz questions,ask questions,basic knowledge quiz,basic science questions,free general knowledge test,general quiz questions with answers,gk knowledge test,good general knowledge questions,good q and a questions,mcq mcqueen,mcq question and answer,mcq questions for medical students,multiple choice questions and answers,multiple choice questions examples,multiple choice questions sample,multiple choice questions with answers,multiple choice quiz questions,multiple choice test questions in english,multiple question quiz,online general knowledge quiz,practice multiple choice questions,q&a questions,quiz questions with answers,science practice,science quiz questions and answers,science test,the general knowledge