Question

A physical quantity is measured and the result is expressed as nu where u is the unit used and n is the numerical value. If the result is expressed in various units then,
(a) n ∝ size of u (b) n ∝ u2 (c) n ∝ √u (d) n ∝ 1/u
Concept of Physics - 1 , HC VERMA , Chapter "Introduction to Physics". Objective Question

Answer 1

Hello Dear.

The correct answer is (d) n ∝ 1/u
Reason/Explanation:- 

-Let us take an example of mass ,suppose if a body has a mass of 20 kg . (In this 20 is the numerical value and kg is the unit) So if we decrease the size of the unit , Say kg to g then the numerical value will be 20000. 
20 kg = 20000 g.

-If the size of the unit Kg will be increased from kg to Quintal then the numerical value will be 0.2 .

20 kg = 0.2 Quintal.

from this example we can say that if the unit is increasing then the numerical value  is decreasing & if the unit is decreasing then the numerical value of  is increasing.

∴ numerical value, n ∝ 1/u
Thus it is proved.

Hope it Helps.

Answer 2

Answer:

D-n∝1/u...=n∝1u^-1.........=n=K1u^-1

Explanation: