Center Of Gravity And Moment Of Inertia(Mechanics Of Materials ) Questions and answers for exam Preparation

Question 1. The point at which the total area of a plane figure is asssumed to be concentrated is called ____________

Centroid
Centre of gravity
Central point
Inertial point

Explanation:-

Answer: Option A. -> Centroid
Answer: (a).Centroid

Question 2. Where will be the centre of gravity of a uniform rod lies?

At its end
At its middle point
At its centre of its cross sectional area
Depends upon its material

Explanation:-

Answer: Option B. -> At its middle point
Answer: (b).At its middle point

Question 3. Where will be the center of gravity of an I section will be if the dimension of upper web is 2x10cm, lower web is 2×20 and that of flange is 2x15cm If the y-axis will pass through the center of the section?

7.611cm
9.51cm
9.31cm
11.5cm

Explanation:-

Answer: Option B. -> 9.51cm
Answer: (b).9.51cm

Question 4. Where the center of gravity of a circle lies?

At its centre
Anywhere on its radius
Anywhere on its circumference
Anywhere on its diameter

Explanation:-

Answer: Option A. -> At its centre
Answer: (a).At its centre

Question 5. The center of gravity of a circle of radius 10 cm will be _____________

At its center of the diameter
At the center of the radius
Anywhere on the circumference
Anywhere in its area

Explanation:-

Answer: Option A. -> At its center of the diameter
Answer: (a).At its center of the diameter

Question 6. What is the moment of inertia of a triangular section about the base?

bh²/12
bh³/12
bh³/6
bh²/6

Explanation:-

Answer: Option B. -> bh³/12
Answer: (b).bh³/12

Question 7. What is the moment of inertia of a triangular section about an axis passing through C.G. and parallel to the base?

bh³/12
bh³/24
bh³/36
bh³/6

Explanation:-

Answer: Option C. -> bh³/36
Answer: (c).bh³/36

Question 8. What will be the moment of inertia of a circle in cm⁴ of diameter is 10cm?

340
410
460
490

Explanation:-

Answer: Option D. -> 490
Answer: (d).490

Question 9. What is the product of the mass and the square of the distance of the center of gravity of the mass from an axis?

Moment of inertia
Mass moment of inertia
Center of gravity
Product of inertia

Explanation:-

Answer: Option B. -> Mass moment of inertia
Answer: (b).Mass moment of inertia

Question 10. What will be the difference between MOI of two triangle sections is in 1st, MOI is taken about its base and in 2nd MOI is taken about its centroid?

bh³/12
bh³/18
bh³/36
bh³/24

Explanation:-

Answer: Option B. -> bh³/18
Answer: (b).bh³/18