In defining the standard of length, we have to specify the temperature at which the measurement should be made. Are we justified in calling length a fundamental quantity, if another physical quantity (temperature) has to be specified in choosing a standard?

In difining the standerd of length, we have to specify the temperature at which the measurement should be made. Are we justified in calling length a fundamental quantity, if another physical quantity (temperature) has to be specified in choosing a standeard?

Can we have physical quantities having magnitude and direction which are not vectors?

Assertion (A): Temperature is a fundamental quantity in SI system. Reason (R ): In other systems of measurement only mass, length and time are fundamental quantities.

The process of measurement is basically a process of comparison. The chosen standard of measurement of a quantity, which has essentially the same nature as that of the quantity is called unit of the quantity. Magnitude of a quantity (Q) = size of its unit (u)xx number of times (n) this unit is contained in the quantity. i.e. Q = nu As magnitude of a quantity remains the same, whatever be its units of measurement, therefore, Q = n_1u_1 = n_2 u_2 Read the above passage and answer the following questions : (i) The value of acceleration due to gravity (g) = 9.8 m//s^2 How do you express it in km//hr^2 ? (ii) Our world is a game of numbers. Do you agree ? Justify.