An Iso – Quant Curve always slopes downward from left to right. i.e., It should always have a Negative Slope

This is because, if producer wants to increase the proportion of one factor, it is possible only by reducing the proportion of another factor because of limited resources. The negative slope of Isoquants implies substitutability between the inputs. It means that if one of the inputs is reduced, the other inputs has to be so increased that the total output remains unaffected. To represent this concept, it should always slope downward. This can be explained with the help of a diagram:

An Iso – Quant will be always convex to the origin

The Law of Diminishing Marginal Rate of Technical Substitution (MRTS) could be explained only if it is convex to the origin. The rate at which one factor is substituted for another factor is known as Technical Substitution.

An Iso-Quant curve drawn to the right hand side of an existing Iso-Quant curve represents higher output

If the manufacturer selects combination M, he would be using 2 units of capital and 4 units of labour, but if he selects combination N, he will be using 4 units of capital and 4 units of labour. Higher the inputs higher would be the output.

The collection of iso-quant curves/the family of iso-quants, is known as “Iso-Quants Map”. In an iso-quants map, an iso-quant curve at the extreme right represents highest level of out put and the curve at the extreme left represents lowest amount of out put. Hence IQ4>IQ3>IQ2>IQ1.

No two Iso-Quant curves should intersects each other

Each iso-quant curve represents a particular level of output and iso-quant curve to the right represents higher output. If they intersect each other, at one point both will give the same level of out put, which is untrue.

No Iso-Quant curve should touch the horizontal or either the vertical axis

The basic assumption is that the producer will use a combination of factor inputs. If an Iso-Quant curve touches either vertical or horizontal axis, this assumption will be violated.

The Iso-Quant curves need not be parallel to each other

The iso-quant curves need not be parallel to each other because the marginal rate of Technical Substitution mayn’t be the same in all the iso-quant curves. Hence it is not a necessary condition that all the iso-quant curves should be parallel to each other.