The age of a tree can be known by examining

Which of the following is a mineral?

Pick up the polymineralic rock from the following:

Softer variety of steel may be obtained by

Which of the following stone is best suited for construction of piers and abutments of a railway bridge?

The proportions of charcoal, saltpetre and sulphur in gun powder by weight, are respectively:

The rocks which are formed due to pouring of magma at the earth's surface are called

The vehicle used in case of enamel paints is usually

Which of the following is the purest form of iron?