Flexural Strength of Sections

Q. The beams, one having square cross-section and another circular cross- section, are subjected to the same amount of bending moment. If the cross sectional area as well as the material of both the beams are the same then

1. maximum bending stress developed in both the beams is the same
2. the circular beam experience more bending stress than the square one
3. the square beam experience more bending stress than the circular one
4. as the material is same both beams will experience same deformation

Q. The ratio of the flexural strength of two beams of square cross-section, the first beam being placed with its top and bottom sides horizontally and the second beam being placed with one diagonal horizontally, is

1. $\sqrt{3}$
2. $1/\sqrt{3}$
3. $1/\sqrt{2}$
4. $\sqrt{2}$

Q. Two beams carrying identical loads, simply supported, are having same depth but beam A has double the width as compared to that of beam B. The ratio of the strength of beam A to that of beam B is

1. 1/2
2. 1/4
3. 2
4. 4

Q. A high strength steel band-saw of 90 mm width and 0.5 mm thickness runs over a pulley of 500 mm diameter. Assuming E = 200 GPa, the maximum flexural stress developed would be

1. 100 MPa
2. 200 MPa
3. 400 MPa
4. 500 MPa

Q. The span and the material of the two beams A and B are the same. The area of cross section of the two beams are equal. The cross section is square. In the case of beam A, the plane of moment is parallel to the sides of the square and in the case of beam B, the plane of moment coincides with the diagonal as shown in the given figure.

Consider the following inferences from the above data:

1. For the same loading, the deflection of the beam B is smaller than that of beam A.
2. If the load on the two beams is the same, then the maximum stress in beam B is greater than that in beam A.
3. Beam A can resist smaller load than beam B.
4. Flexural rigidity of both the beams is equal.

Which of these inferences are incorrect?

1. 2 and 4
2. 1 and 3
3. 1 and 4
4. 2, 3 and 4

Q.

Find the missing dimension of the cylinder at the right. Round your answer to the nearest whole number.

$V=600,000c{m}^3$

Q.

The Dimensional Formula for Youngs Modulus Is

Q. A 450 mm long plain concrete prism is subjected to the concentrated vertical loads as shown in the figure. Cross section of the prism is given as 150 mm x 150 mm. Considering linear stress distribution across the cross-section, the modulus of rupture(expressed in MPa).

1. 3

Q.

The modulus of elasticity is dimensionally equivalent to

1. strain

2. force

3. stress

4. coefficient of viscosity

Q. A test is conducted on a beam loaded by end couples. The fibres at layer CD are found to lengthen by 0.03 mm and fibres at layer AB shorten by 0.09 mm in 20 mm gauge length as shown in the given figure. Taking $E=2\times {10}^{5}N/m{m}^2$, the flexural stress at top fibres would be

1. $900N/m{m}^{2}tensile$
2. $1000N/m{m}^{2}tensile$
3. $1200N/m{m}^{2}tensile$
4. $1200N/m{m}^{2}compressive$

Q. A homogeneous prismatic simply supported beam is subjected to a point load F. The load can be places anywhere along the span of the beam. The very maximum flexural stress developed in the beam is

1. $\frac{3FL}{2B{D}^2}$
2. $\frac{3FL}{4B{D}^2}$
3. $\frac{2FL}{3B{D}^2}$
4. $\frac{4FL}{3B{D}^2}$