Strength Of Materials In Me - Practice Test

[#256] The ductility of the material __________ with the decrease in percentage elongation of a specimen under tensile test.

(A) Increases

(B) Decreases

(C) Remain same

(D) None of these

Correct Answer

(B) Decreases

[#257] The total elongation produced in a bar of uniform section hanging vertically downwards due to its own weight is equal to that produced by a weight

(A) Of same magnitude as that of bar and applied at the lower end

(B) Half the weight of bar applied at lower end

(C) Half of the square of weight of bar applied at lower end

(D) One fourth of weight of bar applied at lower end

Correct Answer

(B) Half the weight of bar applied at lower end

[#258] If the modulus of elasticity for a given material is twice its modulus of rigidity, then bulk modulus is equal to

(A) 2C

(B) 3C

(C) $$frac{{2{ ext{C}}}}{3}$$

(D) $$frac{{3{ ext{C}}}}{2}$$

Correct Answer

(C) $$frac{{2{ ext{C}}}}{3}$$

[#259] A steel bar of 5 mm is heated from 25°C to 45°C and it is free to expand. The bar will induce

(A) No stress

(B) Shear stress

(C) Tensile stress

(D) Compressive stress

Correct Answer

(A) No stress

Explanation

Solution: Stress is nothing but the resisting force since due to temperature rise body will expand and if this expansion due to temperature change is restricted then only resisting stress (thermal stress) will come into play since expansion is not restricted that's why no stress is occurring.

[#260] For a beam, as shown in the below figure, the deflection at C is (where E = Young's modulus for the beam material and $$I$$ = Moment of inertia of the beam section.)

(A) $$frac{{{ ext{W}}{l^3}}}{{48{ ext{E}}I}}$$

(B) $$frac{{{ ext{W}}{{ ext{a}}^2}{{ ext{b}}^2}}}{{3{ ext{E}}Il}}$$

(C) $$frac{{{ ext{Wa}}}}{{{ ext{a}}sqrt 3 { ext{E}}Il}} imes {left( {{l^2} - {{ ext{a}}^2}} ight)^{frac{3}{2}}}$$

(D) $$frac{{5{ ext{W}}{l^3}}}{{384{ ext{E}}I}}$$

Correct Answer

(B) $$frac{{{ ext{W}}{{ ext{a}}^2}{{ ext{b}}^2}}}{{3{ ext{E}}Il}}$$

Explanation

Solution:

Strength Of Materials In Me - Study Mode

[#256] The ductility of the material __________ with the decrease in percentage elongation of a specimen under tensile test.

Correct Answer

[#257] The total elongation produced in a bar of uniform section hanging vertically downwards due to its own weight is equal to that produced by a weight

Correct Answer

[#258] If the modulus of elasticity for a given material is twice its modulus of rigidity, then bulk modulus is equal to

Correct Answer

[#259] A steel bar of 5 mm is heated from 25°C to 45°C and it is free to expand. The bar will induce

Correct Answer

Explanation

[#260] For a beam, as shown in the below figure, the deflection at C is (where E = Young's modulus for the beam material and $$I$$ = Moment of inertia of the beam section.)

Correct Answer

Explanation