Spalling tendency of refractories is reduced by increasing its________?

Nominal size of the discharge pipe of a pump is usually ________ the nominal size of the inlet pipe?

Very small pressure difference (< 5 mm water column) can be most conveniently measured by a/an ________ manometer?

Temperature of molten pig iron (1450°C) and molten slag (1500°C) flowing out of a blast furnace is measured by a/an________?

TLV of aldrin in public water supply system is about ________ μg/litre?

Carbon percentage is the same in cast iron and________?