Tag: science & technology

After Albert Einstein's death in 1955, pathologist Thomas Harvey removed his brain during the autopsy without the family's permission. The brain was preserved and sectioned for scientific study, with Harvey keeping portions of it in jars for decades. This controversial act led to extensive research on Einstein's brain structure to understand his exceptional intellect.

To solve this question, the user needs to know about the basic terminologies and operations of a lathe machine.

The feed rate in a lathe machine refers to the distance that a cutting tool advances into the workpiece with each revolution of the lathe spindle. It is typically expressed in millimeters per revolution (mm/rev).

Option A is correct because feed rate is generally given in millimeters per revolution (mm/rev). This means that for every complete revolution of the lathe spindle, the cutting tool advances a certain distance along the workpiece.

Option B is incorrect because the feed rate is not typically given in millimeters per degree. Degrees are used to measure angles, not distances.

Option C is incorrect because simply giving the distance in millimeters does not take into account the number of revolutions of the lathe spindle that are required to move the cutting tool that distance.

Option D is incorrect because RPM (revolutions per minute) is a measurement of the speed of the lathe spindle, not the feed rate.

Therefore, the correct answer is:

The Answer is: A. mm per revolution

Rapping allowance on a pattern is provided to ensure easy withdrawal of the casting from the mold. Rapping involves loosening or vibrating the pattern slightly before removal to break the adhesion between the pattern and the sand mold, preventing damage to either the pattern or the mold cavity during withdrawal.

Upsetting is a forging operation where the length of a workpiece is reduced while increasing its cross-sectional area. It is typically performed by hammering or pressing the end of a hot metal workpiece to create an enlarged section, commonly used in making bolt heads, rivet heads, and other fasteners.

A reducing flame (also called carburizing flame) in oxyacetylene welding is obtained with excess acetylene. This flame has an inner cone, a feathered intermediate zone, and an outer flame, characterized by a deficiency of oxygen which prevents the burning of all available acetylene, creating a reducing atmosphere that prevents oxidation.

Brasses and bronzes are copper-based alloys that are welded using a neutral flame, which has equal proportions of oxygen and acetylene completely burned. A neutral flame produces no chemical effect on the metal, preventing oxidation or decarburization, which is crucial for welding these non-ferrous alloys that are sensitive to chemical changes during heating.

Surface plates are precision reference surfaces used in metrology and manufacturing. Granite is one of the primary materials used for making surface plates due to its exceptional stability, resistance to wear, low thermal expansion, vibration damping properties, and ability to maintain a perfectly flat surface over long periods of time.

In industrial engineering and process mapping (ASME standards), a circle represents an operation, a square represents inspection, an arrow represents transport, and an inverted triangle represents permanent storage.

Electrode coating provides protective atmosphere through shielding gases, stabilizes the arc for better weld quality, and reduces oxidation of molten metal. Increasing cooling rate is not a function of coating - cooling rate depends on heat input, material thickness, and preheating, not the electrode coating itself.

Feeler gauges are precision measurement tools consisting of multiple thin metal strips of known thicknesses. They are specifically designed to measure small gaps or clearances between mating surfaces, such as piston rings, valve clearances, or bearing fits. They cannot measure plate thickness, screw pitch, or curvature radius.