Two mark Questions and Answers

TWO MARK QUESTIONS AND ANSWERS

1. Define principal stresses and principal plane.

Principal stress: 

The magnitude of normal stress, acting on a principal planes are known as principal stresses.

Principal planes: 

The planes which have no shear stress are known as principal planes.

2. On a principal plane, ――― stress is zero.

Ans. Shear stress.

3. The angle between the principal planes and the planes of maximum shear stress is ―――

Ans. 45°

4. The shear stress on a principal planes are ―――

Ans. Zero

5. The angle between the principal planes are ―――

Ans. 90%

6. Give the expression for maximum shear stress in a two dimensional stress system.

7. What is the radius of Mohr's circle?

Radius of Mohr's circle is equal to the maximum shear stress.

8. A bar of cross sectional area 600 mm2 is subjected to a tensile load of 50 kN applied at each end. Determine the normal stress on a plane inclined at 30° to the direction of loading.

A = 600 mm2

Load, P = 50 kN

θ = 30°

9. Give the expressions for stresses on an inclined plane when it is subjected to a axial pull.

10. What is the use of Mohr's circle?

It is used to find out the normal, tangential, resultant stresses and principal stress and their planes.

11. What are the planes along which the greatest shear stresses occur?

Greatest shear stress occurs at the planes which is inclined at 45° to its normal. 

12. Write the expressions for a normal stress on an inclined plane in a block which is subjected to two mutually perpendicular normal stresses and shear stresses?

13. At a point in a strained material is subjected to a compressive stress of 100 N/mm2 and shear stress of 60 N/mm2. Determine graphically or otherwise the principal stresses.

14. In case of equal like principal stresses, what is the diameter of the Mohr's circle?

Zero.

15. What is the value of maximum shear stress when the principal stresses are σ1 compression and tension?