General Engineering – MCQ from Study Material (Part 1)

The Method of Sections allows you to make a cut through the members of interest and solve for their forces directly using rigid body equilibrium, without solving for forces in other parts of the truss.

Simple trusses lack redundant members, so there is no alternative path for loads to be distributed if one member fails, leading to a chain reaction collapse.

By driving a wedge between objects, the normal forces exerted by the wedge's inclined surfaces are much larger than the force used to drive it, providing a mechanical advantage.

This is the perpendicular axis theorem for an area, which correctly states that the polar moment of inertia about an origin O is the sum of the moments of inertia about two perpendicular axes passing through O.

This is the key assumption. Since all forces intersect at a single point, they can only cause translation, not rotation, so the object's dimensions do not matter for the analysis.

The Law of Cosines (C2=A^2+B^2−2ABcos(c)) directly relates two sides and their included angle to the third side, which is perfect for this situation.

This is correct. The value of the shear at any point is equal to the slope of the moment diagram at that point.

Real forces act over an area, but for calculation purposes, they are often simplified to an equivalent force acting at one point.

These three components fully describe the internal reactions required to keep a section of a 2D beam in equilibrium: axial force (normal), transverse force (shear), and rotational effect (moment).

By subtracting the hole's area and its first moment of area (Axˉ), its effect is correctly removed from the overall shape's properties.

This means there are more constraints than necessary for equilibrium, and the forces cannot be solved using statics alone.

The pressure is given by P=ρgh, where h is the depth. This shows a direct linear relationship between pressure and depth.

The lead defines the mechanical advantage of the screw, relating rotational motion to linear motion.

The area moment of inertia is calculated by integrating an area element multiplied by the square of its distance from an axis (Ix​=∫y2dA), resulting in units of length to the fourth power.

The Law of Sines and Law of Cosines are specifically used for solving oblique triangles, where the Pythagorean theorem and SOH-CAH-TOA do not apply directly.

The right-hand rule is the standard convention for finding the direction of the vector that results from A×B, which is perpendicular to both A and B

This precise definition captures the nature of a couple, which produces a pure moment without any net translation force.

This is the fundamental condition for particle equilibrium, expressed as ΣF=0. It ensures there is no net force to cause acceleration.

The theorem provides a simple formula (I=Iˉ+Ad2) to shift the axis of calculation from the centroid to any other parallel axis.

The Coulomb friction model states that the maximum static friction is the product of the coefficient of static friction and the normal force (Fmax​=μs​N).

The centroid is the geometric or arithmetic mean position of all the points in the shape.

Frames are designed to support loads without moving, whereas machines are designed to transmit and modify forces, often involving moving parts to gain mechanical advantage.

This is the essence of Varignon's Theorem, which allows a complex moment calculation to be broken down into simpler ones using the force's components.

For equilibrium, the forces on a two-force member must be equal, opposite, and collinear, acting along the line connecting the two points.

The cross product produces a vector whose direction is mutually perpendicular to the two original vectors, as determined by the right-hand rule.

This is the core purpose of an FBD, allowing the application of equilibrium equations by clearly showing all forces and moments the body is subjected to.

As the text explains, a moment (called a torque by physicists) is the rotational tendency of a force and is what causes a change in angular velocity.

This is the idealised assumption made in statics, where internal deformations are considered negligible for the purpose of analysing external forces and equilibrium.

The dot product is calculated as ∣A∣∣B∣cosθ. Since the angle θ between perpendicular vectors is 90∘, and cos(90∘)=0, the result is zero.

The text, particularly the poem, emphasizes that in engineering, pounds are treated as a unit of force (weight), not mass.

Vectors represent physical quantities like force that require both a magnitude (how much) and a direction, whereas scalars like mass or time are fully described by their magnitude.