If an instrument has cramped scale for larger values, then it follows

square law
logarithmic law
uniform law
none of the above

The correct answer is B. logarithmic law.

A logarithmic scale is a scale that expresses a value as a power of a fixed value, the base. The logarithm of a number is the power to which the base must be raised to get that number. For example, the logarithm of 100 to the base 10 is 2, because 10 raised to the power of 2 is 100.

A logarithmic scale is often used to represent large numbers, because it can compress a large range of values into a smaller space. For example, the Richter scale is a logarithmic scale that is used to measure the magnitude of earthquakes. The Richter scale is logarithmic because the difference between two earthquakes with magnitudes of 6 and 7 is much greater than the difference between two earthquakes with magnitudes of 5 and 6.

A square law is a relationship between two variables in which the value of one variable is proportional to the square of the value of the other variable. For example, the force of gravity between two objects is proportional to the square of the distance between them.

A uniform law is a relationship between two variables in which the value of one variable is directly proportional to the value of the other variable. For example, the speed of a car is proportional to the amount of gas that is being used.

In conclusion, the correct answer is B. logarithmic law.