Question 1: Describe what an orthographic projection is and explain its purpose in technical drawing.

Answer: An orthographic projection is a method of representing a three-dimensional object on a two-dimensional plane through multiple views, typically front, top, and side. Its purpose is to provide clear and accurate details of the object's shape and dimensions from different angles.

Question 2: You are given a simple 3D shape: a rectangular box with a length of 100mm, width of 50mm, and height of 40mm. Draw the front, top, and side views of this box in the space provided.

Answer: The front view shows the height and width: a rectangle 50mm wide and 40mm tall. The top view shows the length and width: a rectangle 100mm long and 50mm wide. The side view shows the length and height: a rectangle 100mm long and 40mm tall.

Question 3: Sketch a side view of a cone with a height of 150mm and a base diameter of 100mm.

Answer: A side view of the cone should be a triangle with a height of 150mm and a base width of 100mm, with a smooth curved line representing the cone's sloping surface.

Question 4: Draw an isometric view of a cube with each side measuring 50mm.

Answer: The correct sketch shows a cube with all edges equal to 50mm, drawn in isometric projection with three visible faces, each face being a rhombus, giving a 3D effect.

Question 5: Explain the difference between a plan view and an elevation view in orthographic drawing.

Answer: A plan view shows the object from above, looking down, displaying the layout and footprint. An elevation view shows the object from the front or side, displaying height and external features.

Question 6: Draw a detailed top view of a simple L-shaped bracket with the following dimensions: the longer arm is 80mm long and 20mm wide, and the shorter arm is 50mm long and 20mm wide, with a 10mm connecting section.

Answer: The top view should clearly depict the L-shape with accurate lengths and widths, showing the connecting section with a 10mm overlap, and all lines should be straight and clean.

Question 7: Identify and label three key features that should be included in an orthographic drawing of a mechanical gear.

Answer: Key features include the teeth, the central hole (bore), and the outer rim or face of the gear.

Question 8: Sketch a cross-section of a cylinder with a diameter of 60mm and height of 80mm, showing internal features if any.

Answer: The cross-section should be a circle with a diameter of 60mm, with the side profile showing the height of 80mm. Internal features such as a hollow center could be included if specified.

Question 9: Describe how you would convert a 3D object into orthographic views for technical drawing purposes.

Answer: To convert a 3D object into orthographic views, identify each main view (front, top, side), then project the features onto the respective planes using projection lines, ensuring all dimensions are accurate and aligned.

Question 10: Sketch a simple shape that combines a cylinder and a rectangular block on top, showing the front view and top view in the space provided.

Answer: The front view shows a rectangular block with a cylinder on top, with the cylinder's height and diameter clearly indicated. The top view shows the rectangular base with the circle of the cylinder positioned centrally or as specified.

Question 11: List three common mistakes students make when drawing orthographic projections and how to avoid them.

Answer: Common mistakes include: incorrect alignment of views, inconsistent or missing dimensions, and misproportioned features. To avoid these, carefully plan the views, double-check measurements, and use light construction lines for accuracy.