Question

The Law of Variable Proportions is applicable only in the:

• A. Long run
• B. Short run
• C. Very long run
• D. Both short and long run

Hint:

Law of Variable Proportions: \[ \text{Short Run} \Rightarrow \text{Applicable} \] \[ \text{Long Run} \Rightarrow \text{Not Applicable} \] Reason: In the short run some factors remain fixed.

Answer 1

The Correct Option is B

Concept: The Law of Variable Proportions explains how output changes when one factor of production is varied while other factors remain fixed. It is one of the most important laws of production studied in microeconomics.

Step 1: Understand the meaning of the law.
Suppose a farmer owns a fixed amount of land. If additional units of labour are employed on the same land, total output will change. Initially output increases rapidly, then increases at a decreasing rate, and eventually may decline. This phenomenon is explained by the Law of Variable Proportions.

Step 2: Identify the condition required for the law.
The law operates only when:
• At least one factor is fixed.
• At least one factor is variable.
• Technology remains unchanged. Examples:
• Land fixed, labour variable.
• Building fixed, workers variable.
• Machinery fixed, raw material variable.

Step 3: Relate this condition to time period.
In the short run:
• Some factors remain fixed.
• Some factors can be varied. Therefore the law can operate. In the long run:
• All factors are variable.
• No factor remains fixed. Hence the Law of Variable Proportions does not apply in the long run.

Step 4: State the conclusion.
Since the law requires fixed and variable factors simultaneously, it applies only in the short run. Therefore, \[ \boxed{\text{Short Run}} \] Hence the correct answer is \[ \boxed{\text{Option (B)}} \]