Engineering Mechanics - Practice Test

[#61] A machine having an efficiency less than 50%, is known as

(A) Reversible machine

(B) Non-reversible machine

(C) Neither reversible nor non-reversible machine

(D) Ideal machine

Correct Answer

(B) Non-reversible machine

[#62] Which is the correct statement about law of polygon of forces?

(A) If any number of forces acting at a point can be represented by the sides of a polygon taken in order, then the forces are in equilibrium

(B) If any number of forces acting at a point can be represented in direction and magnitude by the sides of a polygon, then the forces are in equilibrium

(C) If a polygon representing forces acting at a point is closed then forces are in equilibrium

(D) If any number of forces acting at a point can be represented in direction and magnitude by the sides of a polygon taken in order, then the forces are in equilibrium

Correct Answer

(D) If any number of forces acting at a point can be represented in direction and magnitude by the sides of a polygon taken in order, then the forces are in equilibrium

[#63] Which of the following is an equation of linear motion? (where, u and v = Initial and final velocity of the body, a = Acceleration of the body and s = Displacement of the body in time t seconds.)

(A) v = u + at

(B) s = ut + $$frac{1}{2}$$ at 2

(C) v 2 = u 2 + 2as

(D) All of these

Correct Answer

(D) All of these

[#64] The moment of inertia of a thin disc of mass ‘m’ and radius ‘r’, about an axis through its center of gravity and perpendicular to the plane of the disc is

(A) $$frac{{{ ext{m}}{{ ext{r}}^2}}}{2}$$

(B) $$frac{{{ ext{m}}{{ ext{r}}^2}}}{4}$$

(C) $$frac{{{ ext{m}}{{ ext{r}}^2}}}{6}$$

(D) $$frac{{{ ext{m}}{{ ext{r}}^2}}}{8}$$

Correct Answer

(A) $$frac{{{ ext{m}}{{ ext{r}}^2}}}{2}$$

[#65] If three forces acting in different planes can be represented by a triangle, these will be in

(A) Non-equilibrium

(B) Partial equilibrium

(C) Full equilibrium

(D) Unpredictable

Correct Answer

(A) Non-equilibrium

Engineering Mechanics - Study Mode

[#61] A machine having an efficiency less than 50%, is known as

Correct Answer

[#62] Which is the correct statement about law of polygon of forces?

Correct Answer

[#63] Which of the following is an equation of linear motion? (where, u and v = Initial and final velocity of the body, a = Acceleration of the body and s = Displacement of the body in time t seconds.)

Correct Answer

[#64] The moment of inertia of a thin disc of mass ‘m’ and radius ‘r’, about an axis through its center of gravity and perpendicular to the plane of the disc is

Correct Answer

[#65] If three forces acting in different planes can be represented by a triangle, these will be in

Correct Answer