The maximum temperature that can be achieved in blast furnace is
upto 5000 K
upto 1200 K
upto 2200 K
upto 1900 K
To determine the correct answer, let's explore the fundamental concept of a blast furnace and its operation in the context of temperature.
A blast furnace is a crucial component in the process of extracting iron from its ores. Its primary function is to smelt iron ores to produce iron. The temperatures required in a blast furnace can vary significantly, especially since it involves chemical reactions that reduce iron oxides to iron.
The highest temperature achieved within the blast furnace occurs at the bottom, near the tuyeres where the combustion of coke with added hot air occurs. This zone is crucial for the accurate melting of iron. The range of operational temperatures in a properly-functioning blast furnace is generally between 1600 K and 1900 K.
This leads us to analyze the given options:
Given the standard operation of a blast furnace, the best plausible choice among the options is upto 1900 K. Therefore, the initially indicated "correct" answer, upto 1200 K, appears to be incorrect, and upto 1900 K should be the correct answer based on practical knowledge of blast furnace operation.
A sphere of radius R is cut from a larger solid sphere of radius 2R as shown in the figure. The ratio of the moment of inertia of the smaller sphere to that of the rest part of the sphere about the Y-axis is : 
AB is a part of an electrical circuit (see figure). The potential difference \(V_A - V_B\), at the instant when current \(i = 2\) A and is increasing at a rate of 1 amp/second is:
Minerals are the naturally occurring, homogeneous inorganic solid substances. They are having a definite chemical composition and crystalline structure, hardness and color. For example, copper pyrite, calamine, etc.

Impurities in an ore are called gauge. The removal of a gauge from the ore is called concentration ore.
Several steps are involved in the extraction of pure metal from ores. Major steps are as follows –