Objective Questions and Answer: Mechanics & Strength of Materials 1

Subject: Mechanics & Strength of Materials

**Part 1: Objective questions and answers of Mechanics & Strength of Materials**

**Q1. A force while acting on a body may**

a) Change its motion

b) Balance the forces, already acting on it

c) Give raise to the internal stresses in it

d) All of these

**Q2. In order to determine the effects of a force, acting on a body, we must know**

a) Magnitude of the force

b) Line of action of the force

c) Nature of the force i.e. Whether the force is push or pull

d) All of the above

**Q3. The unit of force in S.I. system of units is**

a) Dyne

b) Kilogram

c) Newton

d) Watt

**Q4. One kg force is equal to**

a) 7.8 N

b) 8.9N

c) 9.8N

d) 12N

**Q5. The algebraic sum of the resolved parts of a number of forces in a given direction is equal to the resolved part of their resultant in the same direction. This is known as**

a) Principle of independence of forces

b) Principle of resolution of forces

c) Principle of transmissibility of forces

d) None of these

**Q6. Concurrent forces are those forces whose lines of action**

a) Lie on the same line

b) Meet at one point

c) Meet on the same plane

d) None of these

**Q7. The forces, which meet at one point and their lines of action also lie on the same plane, are known as**

a) Coplanar concurrent forces

b) Coplanar non-concurrent forces

c) Non-coplanar concurrent forces

d) Non-coplanar non-concurrent forces

**Q8. The forces which do not meet at one point and their lines of action do not lie on the same plane are known as**

a) Coplanar concurrent forces

b) Coplanar non-concurrent forces

c) Non-coplanar concurrent forces

d) None of these

**Q9. Coplanar concurrent forces are those forces which**

a) Meet at one point, but their lines of action do not lie on the same plane

b) Do not meet at one point and their lines of action do not lie on the same plane

c) Meet at one point and their lines of action also lie on the same plane

d) Do not meet at one point, but their lines of action lie on the same plane

**Q10. Non-coplanar concurrent forces are those forces which**

a) Meet at one point, but their lines of action do not lie on the same plane

b) Do not meet at one point and their lines of action do not lie on the same plane

c) Meet at one point and their lines of action also lie on the same plane

d) Do not meet at one point, but their lines of action lie on the same plane

**Q11. Non-coplanar non-concurrent forces are those forces which**

a) Meet at one point, but their lines of action do not lie on the same plane

b) Do not meet at one point and their lines of action do not lie on the same plane

c) Meet at one point and their lines of action also lie on the same plane

d) Do not meet at one point, but their lines of action lie on the same plane

**Q12. According to lami’s theorem**

a) The three forces must be equal

b) The three forces must be at a 120 degree to each other

c) The three forces must be in equilibrium

d) If the three forces acting at a point are in equilibrium, then each force is proportional

to the sine of the angle between the other two

**Q13. The moment of a force**

a) Is the turning effect produced by a force, on the body, on which it acts

b) Is equal to the product of force acting on the body and the perpendicular distance of a point and the line of action of the force

c) Is equal to twice the area of the triangle, whose base is the line representing the force and whose vertex is the point, about which the

a) Moment is taken

d) All of the above

**Q14. If a number of coplanar forces acting at a point be in equilibrium, the sum of clockwise moments must be ______ the sum of anticlockwise moments, about any point.**

a) Equal to

b) Less than

c) Greater than

d) None of the above

**Q15. Varingon’s theorem of moments states that if a number of coplanar forces acting on a particle are in equilibrium, then**

a) Their algebraic sum is zero

b) Their lines of action are at equal distances

c) The algebraic sum of their moments about any point in their plane is zero

d) The algebraic sum of their moments about any point is equal to the moment of their resultant force about the same point.

**Q16. According to the law of moments, if a number of coplanar forces acting on a particle are in equilibrium, then**

a) Their algebraic sum is zero

b) Their lines of action are at equal distances

c) The algebraic sum of their moments about any point in their plane is zero

d) The algebraic sum of their moments about any point is equal to the moment of their resultant force about the same point.

**Q17. For any system of coplanar forces, the condition of equilibrium is that the**

a) Algebraic sum of the horizontal components of all the forces should be zero

b) Algebraic sum of the vertical components of all the forces should be zero

c) Algebraic sum of moments of all the forces about any point should be zero

d) All of the above

**Q18. The forces, whose lines of action are parallel to each other and act in the same directions, are known as**

a) Coplanar concurrent forces

b) Coplanar non-concurrent forces

c) Like parallel forces

d) Unlike parallel forces

**Q19. The three forces of 100N, 200N and 300N have their lines of action parallel to each other but act in the opposite directions. These forces are known as**

a) Coplanar concurrent forces

b) Coplanar non-concurrent forces

c) Like parallel forces

d) Unlike parallel forces

**Q20. Two like parallel forces are acting at a distance of 24mm apart and their resultant is**

**20N. If the lines of action of the resultant is 6mm from any given force, the two forces are**

a) 15N and 5N

b) 20N and 5N

c) 15N and 15N

d) None of these

**Part 1: Objective questions and answers of Mechanics & Strength of Materials**

Q1. Answer d

Q2. Answer d

Q3. Answer c

Q4. Answer c

Q5. Answer b

Q6. Answer b

Q7. Answer a

Q8. Answer d

Q9. Answer c

Q10. Answer a

Q11. Answer b

Q12. Answer d

Q13. Answer d

Q14. Answer a

Q15. Answer d

Q16. Answer c

Q17. Answer d

Q18. Answer c

Q19. Answer d

Q20. Answer a