Question 1: Describe the main features of orthographic projection and explain its purpose in technical drawing.

Answer: Orthographic projection is a method of representing three-dimensional objects in two dimensions using multiple views, typically front, top, and side. Its purpose is to provide clear and accurate representations of an object’s dimensions and shape for manufacturing or construction.

Question 2: Draw the front view of a simple rectangular box measuring 100mm wide, 50mm deep, and 60mm high.

Answer: A correct front view would show a rectangle 100mm wide and 60mm high, with no depth shown in this view. The drawing should be proportionate and neatly outlined.

Question 3: Sketch the top view of a cylindrical object with a diameter of 40mm and a height of 80mm. The object is viewed from above.

Answer: A correct top view would be a circle with a diameter of 40mm, centered within the drawing space. The height is not visible in this view but should be noted in the description.

Question 4: Draw the side view of a wedge-shaped object that is 150mm long, 50mm high at the thick end, tapering to 10mm at the thin end. The height remains consistent across the length.

Answer: A correct side view would show a sloped line starting at 50mm high and gradually decreasing to 10mm over the 150mm length. The outline should clearly depict the tapering shape.

Question 5: Explain why multiple views are necessary in orthographic drawing, and give an example of an object that requires at least three views for complete representation.

Answer: Multiple views are necessary to fully describe all three dimensions of an object, especially when features are not visible from a single perspective. An example is a complex box with internal features or protrusions, which cannot be fully understood from only one view.

Question 6: Sketch an isometric view of a cube measuring 50mm on each side. Ensure your sketch clearly shows the three axes and the shape.

Answer: A correct sketch will depict a cube with all edges equal to 50mm, drawn in isometric projection with axes at 120° angles, showing a clear three-dimensional form.

Question 7: Describe the difference between a plan view and an elevation view in orthographic drawings.

Answer: A plan view shows an object from directly above, highlighting the layout and footprint. An elevation view shows the object from the front or side, illustrating height and vertical features.

Question 8: Sketch the elevation view of a rectangular prism that is 80mm wide, 40mm deep, and 30mm high, with a small rectangular cut-out 20mm wide and 10mm high on the front face.

Answer: A correct sketch will show a rectangle 80mm wide and 30mm high, with a smaller rectangle 20mm wide and 10mm high positioned appropriately on the front face to indicate the cut-out.

Question 9: Draw three orthographic views (front, top, side) of a simple L-shaped bracket measuring 100mm by 50mm by 20mm, with the L-shape extending 50mm in length and 20mm in width.

Answer: A correct set of views would show the L-shape from each perspective, with accurate dimensions, and clearly indicate the shape and features of the bracket.

Question 10: List three common mistakes students make when creating orthographic projections and suggest a way to avoid each.

Answer: Common mistakes include: 1) Incorrectly aligned views—ensure views are properly aligned using projection lines. 2) Missing or inconsistent dimensions—check measurements carefully. 3) Overly cluttered drawings—keep views clean and avoid unnecessary detail.