Home » mcq » Civil engineering » Theory of structures » The maximum deflection due to a load W at the free end of a cantilever of length L and having flexural rigidity E$$I$$, is A. $$\frac{{{\text{W}}{{\text{L}}^2}}}{{2{\text{E}}I}}$$ B. $$\frac{{{\text{W}}{{\text{L}}^2}}}{{3{\text{E}}I}}$$ C. $$\frac{{{\text{W}}{{\text{L}}^3}}}{{2{\text{E}}I}}$$ D. $$\frac{{{\text{W}}{{\text{L}}^3}}}{{3{\text{E}}I}}$$
$$rac{{{ ext{W}}{{ ext{L}}^2}}}{{2{ ext{E}}I}}$$
$$rac{{{ ext{W}}{{ ext{L}}^2}}}{{3{ ext{E}}I}}$$
$$rac{{{ ext{W}}{{ ext{L}}^3}}}{{2{ ext{E}}I}}$$
$$rac{{{ ext{W}}{{ ext{L}}^3}}}{{3{ ext{E}}I}}$$
Answer is Wrong!
Answer is Right!
The correct answer is $\frac{{{\text{W}}{{\text{L}}^3}}}{{3{\text{E}}I}}$.
The maximum deflection due to a load $W$ at the free end of a cantilever of length $L$ and having flexural rigidity $EI$ is given by the following equation:
$$\delta = \frac{{{\text{W}}{{\text{L}}^3}}}{{3{\text{E}}I}}$$
where:
- $\delta$ is the maximum deflection,
- $W$ is the load,
- $L$ is the length of the cantilever,
- $E$ is the Young’s modulus, and
- $I$ is the moment of inertia.
The equation can be derived using the following steps:
- Assume that the cantilever is a uniform beam with a constant cross-section.
- Apply the principle of superposition to find 0 576 512">
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the deflection of the beam due to the load $W$.
The deflection of the beam due to the load $W$ is given by the following equation:
$$\delta = \frac{{M}}{{EI}}$$
where:
$$M = WL$$
where:
$$\delta = \frac{{WL}}{{EI}}$$
- The maximum deflection occurs at the free end of the beam, where the bending moment is maximum.
- The maximum deflection is given by the following equation:
$$\delta = \frac{{{\text{W}}{{\text{L}}^3}}}{{3{\text{E}}I}}$$