Related Questions

The relation between Young's modulus (E), shear modulus (C) and bulk modulus (K) is given by
A $${\text{E}} = \frac{{3{\text{KC}}}}{{3{\text{K}} + {\text{C}}}}$$
B $${\text{E}} = \frac{{6{\text{KC}}}}{{3{\text{K}} + {\text{C}}}}$$
C $${\text{E}} = \frac{{9{\text{KC}}}}{{3{\text{K}} + {\text{C}}}}$$
D $${\text{E}} = \frac{{12{\text{KC}}}}{{3{\text{K}} + {\text{C}}}}$$
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 $$\frac{{2{\text{C}}}}{3}$$
D $$\frac{{3{\text{C}}}}{2}$$
Which of the following relationships is correct for relating the three elastic constants of an isotropic elastic material (where, E = Young's modulus, G = Modulus of rigidity or shear modulus v = Poisson's ratio)?
A E = 2G (1 + v)
B E = G (1 + v)
C $${\text{E}} = \frac{{{\text{G}}\left( {1 + {\text{v}}} \right)}}{2}$$
D E = 2G (1 + 2v)
Gold is 19 times as heavy as water and Copper is 9 times as heavy as water. Calculate the ratio in which these two metals should be mixed so that the mixture is 15 times as heavy as water.
A 40
B 41
C 42
D 43
If p = bearing pressure on projected bearing area, Z = absolute viscosity of lubricant and N = speed of journal, then the bearing characteristic number is given by
A $$\frac{{{\text{ZN}}}}{{\text{p}}}$$
B $$\frac{{\text{p}}}{{{\text{ZN}}}}$$
C $$\frac{{\text{Z}}}{{{\text{pN}}}}$$
D $$\frac{{\text{N}}}{{{\text{Zp}}}}$$
The stiffness of a closely coiled helical spring subjected to an axial load W is equal to (where G = Modulus of rigidity and n = Number of active coils)
A $$\frac{{{\text{G}}{{\text{d}}^4}}}{{8{{\text{D}}^3}{\text{n}}}}$$
B $$\frac{{{\text{G}}{{\text{d}}^3}}}{{8{{\text{D}}^3}{\text{n}}}}$$
C $$\frac{{{\text{G}}{{\text{d}}^4}}}{{4{{\text{D}}^3}{\text{n}}}}$$
D $$\frac{{{\text{G}}{{\text{d}}^4}}}{{8{{\text{D}}^2}{\text{n}}}}$$
When a closely-coiled helical spring of mean diameter (D) is subjected to an axial load (W), the deflection of the spring ($$\delta $$) is given by (where d = Diameter of spring wire, n = No. of turns of the spring and C = Modulus of rigidity for the spring material)
A $$\frac{{{\text{W}}{{\text{D}}^3}{\text{n}}}}{{{\text{C}}{{\text{d}}^4}}}$$
B $$\frac{{2{\text{W}}{{\text{D}}^3}{\text{n}}}}{{{\text{C}}{{\text{d}}^4}}}$$
C $$\frac{{4{\text{W}}{{\text{D}}^3}{\text{n}}}}{{{\text{C}}{{\text{d}}^4}}}$$
D $$\frac{{8{\text{W}}{{\text{D}}^3}{\text{n}}}}{{{\text{C}}{{\text{d}}^4}}}$$
The frictional torque transmitted in a flat pivot bearing, considering uniform wear, is (where μ = Coefficient of friction, W = Load over the bearing and R = Radius of bearing surface)
A $$\frac{1}{2}$$μWR
B $$\frac{2}{3}$$μWR
C $$\frac{3}{4}$$μWR
D μWR
In testing a pile by load test, pile platform is loaded with one and half times the design load and a maximum settlement is noted. The load is gradually removed and the consequent rebound is measured. For a safe pile, the net settlement (i.e. total settlement minus rebound) per tonne of test load should not exceed
A 10 mm
B 15 mm
C 20 mm
D 25 mm
(i) What is global warming? How global warming affects the rapid change of climate? (ii) What are the bad impacts of climate change? (iii) How climate change affects the environment of Bangladesh (iv) How global warming can be minimized (v) What should be the role of students to protect the environment.
A (i) Global warming is the main natural reason and using harmful chemicals in everyday life the main reason created by men. The climate is changing rapidly that result in the rise of the earth's average temperature
B (ii) Climate change impacts include floods, cyclones, storm surges and drought, ice sheets melting which will seriously affect the agriculture and livelihood especially at the poor.
C (iii) Bangladesh is one of the largest deltas in the world which is highly vulnerable to Natural Disasters because of its Geographical location, Fiat and low-lying landscape, Population density, Poverty, Illiteracy, Lack of Institutional setup, etc.
D (iv) To reduce the bad impact of climate change people should be aware of. Tree plantation can reduce global warming which is the main natural reason for climate change. Stop using harmful chemicals can reduce environmental pollution which is the main man
E (v) Students should be careful to protect the environment and raise awareness. Thus the students can play a vital role to reduce bad impact of climate changes.

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