Q1: Brittleness induced due to the presence of sulphur in steel can be reduced by adding

ANS:A - manganese

The brittleness induced due to the presence of sulfur in steel can be reduced by adding manganese. Explanation:

1. Manganese: Manganese is often added to steel as a deoxidizer and desulfurizing agent. When manganese is added to steel, it combines with sulfur to form manganese sulfide (MnS) inclusions. These MnS inclusions have a globular shape and are less harmful compared to elongated sulfur inclusions. This modification helps to reduce the detrimental effects of sulfur on the steel's properties, including brittleness. Additionally, manganese itself can improve the steel's strength and toughness properties.

While magnesium, vanadium, and copper can also influence the properties of steel, they are not typically used specifically to counteract the brittleness induced by sulfur. Magnesium is more commonly used as a grain refiner in aluminum alloys, while vanadium and copper are often added to steel for purposes such as strengthening or improving corrosion resistance, rather than specifically for reducing sulfur-induced brittleness.