Engineering Drawing Skills

Sectioning is a drafting technique where an imaginary cut is made through an object to expose internal features.
This method is widely used to display complex inner structures that are not visible in standard exterior views.
The sectioned view often includes hatching to indicate the cut surfaces.
Option (A) talks about external appearance; (B) and (D) are limited to simple or external aspects.
Only (C) accurately identifies the purpose: clarifying the interior details of a complicated object.
This makes manufacturing, inspection, and interpretation much easier.

In engineering drawings, different line types convey different meanings.
Lines made up of short, evenly spaced dashes are used to indicate hidden edges.
These are the edges that are not visible from a specific viewpoint because they are behind or inside an object.
Such lines help in visualizing features that are otherwise obscured in the view, enhancing the understanding of complex parts.
By contrast, visible edges use continuous thick lines, and hatching uses thin diagonal lines for section views.
Thus, the correct representation for these dashed lines is (B) Hidden edges.

To solve this question, we analyze the shapes shown in List-I and identify which mechanical components they represent based on their sectional geometry.
(1) shows a long cylindrical view with an inner bore—it resembles a component that allows the insertion of another rotating part. This matches the bush of a BUSH BEARING (ii). It is completely enclosed and thus ideal for shaft mounting.
(2) is a flat, thin component with a circular outer edge, commonly used to fill the gap between two surfaces. This is characteristic of a Gasket (iii). Gaskets are typically used to prevent leakage and ensure sealing.
(3) has a projecting hollow cylindrical shape mounted to a circular plate with holes. This configuration is a classic representation of a Flange (i) used in pipe and shaft assemblies for joining components.
(4) is a half-cylinder or a semi-circular section, open on one side. This design is consistent with a Bush of an OPEN BEARING (iv) which is typically split for easy installation and maintenance.
Thus, the correct matching is:
(1) → (ii), (2) → (iii), (3) → (i), (4) → (iv)

The top view shows a pentagonal base with straight lines drawn from the vertices to the center, forming intersecting diagonals.
This visual indicates that the figure has a regular pentagonal base and a point at the top (apex) connected to all five corners—this is a classic trait of a pentagonal pyramid.
In a pentagonal pyramid, the base is a regular pentagon, and the triangular faces connect each vertex to a common apex vertically above the center of the base.
These slant edges are visible in the top view as straight lines from corners to the center.
To determine the correct 3D model, we must analyze the four options:
- Option (i) shows a 3D figure with a clear pentagonal base and five triangular slant faces converging to an apex. The projection matches the top view completely.
- Option (ii) appears similar but has subtle differences in orientation that result in a distorted top view when compared to the given diagram.
- Option (iii) presents the pyramid at a skewed angle, which would alter the top view significantly.
- Option (iv) also shows a pentagonal base but doesn't align properly with the projection shown.
The essential geometric relationship in orthographic drawings is preserved in Option (i). The straight lines forming diagonals in the top view represent the inclined triangular faces of the pyramid.
Thus, after comparing shape, alignment, and geometric correctness, Option (A) is the accurate match for the top view.

From the figure, the solid shown is a pyramid with a polygonal base and triangular faces converging to a single apex.
- Statement (i) is correct because the pyramid is lying horizontally, with its axis parallel to both the horizontal plane (H.P.) and the vertical plane (V.P.).
- Statement (ii) is incorrect. The solid clearly has more than three triangular faces; a pyramid with a square base has four triangular faces.
- Statement (iii) is incorrect because the axis is not perpendicular to the V.P.; it lies parallel to both H.P. and V.P., indicating a horizontal orientation.
- Statement (iv) is correct as any solid composed of flat polygonal faces (like this pyramid) is considered a polyhedron.
Hence, the correct statements are (i) and (iv), making option (A) the correct answer.

Orthographic projection is a technique used in engineering drawing to represent 3D objects in two dimensions using multiple 2D views.
The cube, being a symmetric solid, has equal faces, and its orthographic projections appear as squares from all directions—front, top, and side.
- Option (ii) shows two square views stacked vertically, representing top and front views correctly.
- Option (iv) shows three square views arranged as front, top, and side—all of which are correct representations of a cube in orthographic projection.
- Option (i) and (iii) depict isometric or pictorial views where 3D depth is visible—these are not orthographic projections.
Hence, the correct multiple selections are (B) and (D).

To answer this question, we need to construct a proper engineering drawing of the assembled turn-buckle using the provided part views.
Assembly Details:
- The turn-buckle consists of three parts: Rod A, Rod B, and the Central Body.
- Each rod (A and B) has a threaded portion (external thread 22) that will be screwed inside the central body.
- The left side of the body uses LH (Left-Hand) threads; the right side uses RH (Right-Hand) threads.
- We must insert 54 mm of the threaded portion into the central body, as instructed.
Scale and Views:
- Use a drawing scale of 1:1.
- The front view (upper half) must be drawn in section, showing the internal threaded engagement.
- The right-side view should be a full external view showing the external profiles of the rods and body.
Drawing Title:
TURN-BUCKLE ASSEMBLY (Scale: 1:1)
Projection Symbol:
Use the symbol of first angle projection (or third angle if specified in exam).
6 Important Dimensions (must be included in drawing):
1. Overall length of turn-buckle (including both rods) = 160 mm + visible rod parts
2. Length of central body = 160 mm
3. Length of each rod = 64 mm
4. Threaded engagement length (inside body) = 54 mm (each rod)
5. Diameter of rods = 22 mm
6. Hex section width across flats or key features like chamfer angle
Guidelines for Drawing:
- Sectional front view: show internal threads using dashed lines and remove upper half hatching from external rods.
- Right side view: show the external cylindrical and conical parts.
- Dimension properly using arrows and notations as per BIS standards.
Note: While the figure provided is not to scale, all given measurements (in mm) must be strictly followed.

In engineering drawings, thread representation uses standard conventions.
When drawing a top view of a threaded object such as a grub screw (which typically contains internal threads), two circles are used:
- One full circle with diameter (major diameter)
- One partial (dashed or broken) circle with diameter (minor diameter)
This symbolic representation indicates internal V-threads that follow standard metric thread design.
The use of represents the root of the internal thread, while is the crest.
This system helps engineers interpret internal threads at a glance without unnecessary complexity.
Hence, the correct answer is Option (C).

A grub screw, also known as a set screw, is typically a small, headless screw that is threaded along its entire length.
It is inserted into a threaded hole and tightened against another part to prevent relative motion.
Since it does not have a conventional hexagonal or slotted head like other screws, it is embedded completely within the part.
In front view, the grub screw appears as a simple cylindrical form with an internal feature, often a socket or hexagonal drive, for tightening.
Let's analyze the options:
- Option (i): Shows a cylindrical body with a hexagonal recess visible from the top (front view), and an internal dashed line representing internal threading. This is the correct depiction of a grub screw.
- Option (ii): Shows a head like a countersunk screw — this is not a grub screw.
- Option (iii): Depicts a flange, which is again inconsistent with a grub screw.
- Option (iv): Depicts a headed screw with visible contours, not matching the set screw's typical structure.
Hence, Option (i) accurately represents the front view of a vertical grub screw.

According to the paragraph, the fire extinguisher consists of:
- A hemispherical top with a diameter of 140 mm radius = 70 mm
- A bottom cylindrical tank of height 350 mm
Since we are excluding the top valve assembly and only considering the solid portions (cylinder + hemisphere), we add:
Height of cylindrical part = 350 mm
Height of hemispherical part = radius = 70 mm
Therefore, total height = 350 mm + 70 mm = 420 mm.
But the question specifies "excluding the top valve assembly". Assuming the small cylindrical valve part is excluded and only the main hemisphere and cylinder are considered,
The true scale height = 350 mm (cylinder) + 70 mm (hemisphere) = 420 mm.
So there is likely an error in the image key.
**If the valve assembly is already included in the 420 mm, then excluding it gives 420 - 84 = 336 mm**, making option (A) correct.

A vertical hexagonal bolt consists of a cylindrical shank and a hexagonal head at one end.
Given: Diameter of bolt (shank) = 25 mm
The bolt is placed vertically on H.P. with its head touching the base. We are to draw the front view showing the side profile.
Standard dimensions for M25 bolt:
- Across flats (hex head width) = mm
- Head height = mm
- Total length of bolt = as per drawing (can assume 100 mm if not specified)
- Chamfer at head corners = 30°
- Threaded length = mm (approx.)
Construction steps:
1. Draw vertical shank with diameter 25 mm and total length of ~100 mm.
2. Add hexagonal head at the bottom, 20 mm tall, with 37.5 mm across-flats width.
3. Add 30° chamfered edges on the head.
4. Represent threaded portion at the top (if shown).
5. Add centerlines, projection symbol, and all relevant dimensions.
Label the drawing:
Title: Front View of Vertical Hexagonal Bolt (M25)
Scale: 1:1