Which of the eight core industries carries the highest weight in the core sector index?

The correct answer is B, the National Statistical Office. It works under the Ministry of Statistics and Programme Implementation, gathers production returns from more than a dozen source agencies spread across ministries, and publishes the IIP every month as a Quick Estimate that is revised as fuller data come in. Option A, the Department for Promotion of Industry and Internal Trade, is the wrong answer for the IIP but the right one for a related index, because its Office of the Economic Adviser compiles the Index of Eight Core Industries and the Wholesale Price Index; examiners rely on that overlap. Option C, the Reserve Bank of India, is a heavy user of the IIP in framing monetary policy but does not compile it. Option D, NITI Aayog, is a policy think tank and has no statistical production function of this kind at all.

The correct answer is D, Agriculture. The IIP is confined to the industrial sector and has exactly three components, mining, manufacturing and electricity, which are options A, B and C. Agriculture and the whole of the services sector, which together account for the larger part of India's output, lie outside the index, and that is why a rise in the IIP can never by itself be described as a rise in the growth of the economy. The point is tested in statement form, where a candidate is asked whether the IIP reflects overall economic activity; the answer is that it reflects industrial activity alone. Farm output is tracked instead through crop estimates and the advance estimates of agricultural production, and services through separate indicators, all of which are brought together only in the national accounts.

The correct answer is B, Manufacturing, which carries 77.63 per cent of the weight of the index. Mining, option A, has 14.37 per cent, and electricity, option C, has 7.99 per cent, so the three add up to a hundred. Because manufacturing dominates so heavily, the monthly headline number usually moves with factory output, and a bad month in mining or power can be offset entirely by a good month in factories. Option D, construction, is not a component of the IIP at all, which is the trap in this question; construction activity is reflected only indirectly through the infrastructure and construction goods category of the use-based classification, which measures the production of items such as cement and steel structures rather than building work itself. The weights come from the gross value added shares of the base year, 2011-12.

The correct answer is C, 2011-12. In 2017 the base year of the IIP was shifted to 2011-12, the item basket was refreshed to take in goods that had become important since the previous revision, and the weights were recalculated from the gross value added shares of that year. Option B, 2004-05, was the base of the series that the 2011-12 series replaced, and it is the answer a candidate gives who has memorised the older textbook. Option A, 1993-94, was an earlier base still, used before 2004-05, and it also served as the base year for several other Indian indices of that period. Option D, 2017-18, is only the year in which the revision was announced and has never been a base year for this index. A base year is chosen as a normal year, free of unusual disturbance, so that comparisons are meaningful.

The correct answer is C, about 40 per cent; the precise figure is 40.27 per cent. The eight core industries are the energy and basic material industries on which the rest of manufacturing depends, and because they make up two-fifths of the IIP their monthly index is read as an advance signal of what the fuller index will report a little later. Options A and B, 25 and 33 per cent, understate the share and are offered because candidates often confuse this figure with the share of manufacturing in gross value added or with the forest cover target of a third. Option D, 50 per cent, overstates it; no single group inside the IIP reaches half the weight except manufacturing as a whole, which stands at 77.63 per cent. Remembering the pair 40.27 for the core sector and 77.63 for manufacturing keeps the two apart.